https://wiki.pscs.co.uk/ 2026-05-06T10:13:59+00:00 https://wiki.pscs.co.uk/ https://wiki.pscs.co.uk/_media/wiki:dokuwiki.svg text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:copy_outgoing_mail?rev=1542192349&do=diff Copy Outgoing mail Sometimes people need to copy outgoing mail for various reasons. There are several ways of doing this in VPOP3 depending on your exact requirements: * Message Monitoring - this copies all outgoing, incoming and/or internal mail sent by/to specific users to another specific user text/html 2025-10-14T15:43:01+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/faq:gdpr_hosted_vpop3?rev=1760456581&do=diff GDPR for hosted VPOP3 service (Since Brexit, the UK has “UK GDPR” instead of “EU GDPR”, so this document refers to UK GDPR) Also see GDPR for VPOP3 as most of that applies to the VPOP3 hosting service as well. This Data Processing Agreement is part of our hosted VPOP3 service terms. You can view the revision history by clicking on the 'clock' icon to the right. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:database_backup_failed?rev=1542192349&do=diff Database Backup Failed VPOP3 version 3 and later will, by default, make a backup of the database used by VPOP3 into a file. This uses the PostgreSQL utility 'pg_dump' If an error occurs whilst running this program, VPOP3 will create a 'Database Backup Failed' error message to the administrator. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:database_size?rev=1542192349&do=diff VPOP3 Database Size The VPOP3 directory is stored in the VPOP3\pgsql\data folder and subfolders. If you are concerned about the size of the VPOP3 database, there are several factors which may make the database larger than you would expect: * The VPOP3 database contains a lot more information than just messages in mailboxes. This can include settings, outgoing messages, historical logging information, statistical information for the spamfilter, information about archived messages, etc. Also,… text/html 2025-10-06T15:21:37+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:error_messages?rev=1759764097&do=diff Error Messages This is the place to look if you are trying to trouble shoot a problem and you have received or have access to a specific error message or error code. If instead your problem is that something you think is set up correctly is not working then the best place to look would be the text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:exceptions?rev=1542192349&do=diff Exceptions An exception happens if VPOP3 encounters a problem it did not expect. In some cases it can recover automatically, but in other cases that isn't possible. Common causes VPOP3 2.6 and earlier In VPOP3 2.6 and earlier it was quite common for there to be database corruption problems with the SQLite database which was used in those versions. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:find_ip_address_of_vpop3?rev=1542192349&do=diff Find the IP address of the VPOP3 Computer To find the IP address of the VPOP3 computer, in Windows go to Control Panel -> Network and Sharing Center. Press the Local Area Connection link Then press 'Details'. Look for the 'IPv4 Address' setting. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:no_transport_provider_is_available?rev=1542192349&do=diff Outlook/Windows Messaging reports "No transport provider is available" If Outlook or Windows Messaging reports No transport provider is available when trying to connect to VPOP3, it can mean several things. (This must be a contender for “the world's most meaningless error message text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:outbound_messages_not_appearing_in_monitor?rev=1542192349&do=diff Outbound Messages Not Appearing in Monitor Target Mailbox For VPOP3 to monitor outbound messages it needs to be able to work out that the message is FROM: a user whose mail should be monitored. To do this it has to examine the FROM: address in the message header. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:performance_requirements?rev=1542192349&do=diff Performance Requirements The performance requirements for VPOP3 depends on many factors, so we can't give specific details for any scenario. How to detect limiting factors * Use the Windows Performance Monitor (perfmon.msc) * Add counters for: text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:sender_policy_framework?rev=1542192349&do=diff Sender Policy Framework / SPF SPF is a system used to tell mail servers which IP addresses can send mail from which domains. It is designed to reduce 'spoofing' of email addresses. For instance, if you receive an email message from your bank, your mail software can check that it came from an IP address authorised to send mail from your bank, and treat the message with suspicion if it didn't come from an authorised IP address. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:spam_filter_not_working?rev=1542192349&do=diff Spam filter not working If the VPOP3 spam filter appears not to be working at all, the first thing to do is to look at the message headers of an incoming message to see if the spam filter is being run at all. Check to see if a header line beginning with X-VPOP3-Spam text/html 2020-06-29T10:43:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:upgrade_vpop3_to_version_7?rev=1593427438&do=diff How to upgrade VPOP3 to version 7 or later from version 6 or earlier As usual the process to upgrade is simply to install the later version over your existing installation (do not uninstall anything first). The below is technical information detailing an extra step performed by the installer in this particular upgrade step. text/html 2020-09-03T15:07:34+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:upgrade_vpop3_to_version_8?rev=1599145654&do=diff Upgrading VPOP3 to version 8.x from v7 or earlier VPOP3 v8.x uses PostgreSQL 10 as its database engine, which is the latest supported 32 bit version of PostgreSQL. Later versions of PostgreSQL are 64-bit only, which means we cannot use them while continuing to support 32 bit versions of Windows. text/html 2026-03-18T20:49:54+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:upgrade_vpop3_to_version_9?rev=1773866994&do=diff Upgrading VPOP3 to version 9.x from v7 or v8 VPOP3 v9 and later requires a 64 bit version of Windows 8.1 or later VPOP3 v9.x uses PostgreSQL 18 as its database engine. This can only easily be upgraded from PostgreSQL 9.3 or later, which means it must be an upgrade of VPOP3 v7 or later. If you are using an earlier version of VPOP3, then upgrade it to v8.7 first, then upgrade to v9 or later text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:whitelist_blacklist?rev=1542192349&do=diff Spamfilter Whitelist & Blacklist The VPOP3 spamfilter has a whitelist and a blacklist for sender addresses. It also has a whitelist and blacklist for words/phrases. You can view these lists in the VPOP3 settings by going to Settings -> Spamfilter -> text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:attachment_processing?rev=1542192349&do=diff Settings -> Attachment Processing The Attachment Processing page allows you to configure VPOP3 to perform two distinct functions on messages that contain attachments: * * Filtering The Filtering tab is divided into four main sections: Attachment Filtering text/html 2026-03-16T16:00:10+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/wiki:syntax?rev=1773676810&do=diff Formatting Syntax DokuWiki supports some simple markup language, which tries to make the datafiles to be as readable as possible. This page contains all possible syntax you may use when editing the pages. Simply have a look at the source of this page by pressing text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/faq:gdpr_other_hosting?rev=1542192349&do=diff GDPR for other hosting services (eg web hosting) As a hosted service provider, we are classed as a “Data Processor” under the GDPR regulations. For our hosting services: * Data is held in the UK. Data is not transmitted outside of the EU except at your explicit request or command. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/faq:multiple_vpop3_status_icons?rev=1542192349&do=diff Multiple VPOP3 icons in the taskbar If you reinstall VPOP3 it is possible that you may end up with two VPOP3 Status Monitor icons in the task tray. This doesn't mean that two copies of VPOP3 are running, just that two copies of the VPOP3 Status Monitor are running. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/faq:windows_server_port_conflicts?rev=1542192349&do=diff Windows Server Port Conflicts LDAP Server Conflict When you run VPOP3 on a server edition of Windows you may receive an error saying LDAP server not started - couldn't bind socket port 389 (10048) This error happens because VPOP3 contains an LDAP (Lightweight Directory Access Protocol) server for its global address book functionality, and the Windows 2000/2003 'Active Directory Service' also uses LDAP as its mechanism. These two services are conflicting. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:421_4.3.2_vpop3_smtp_server_access_disabled_-_content_scanner_problem?rev=1542192349&do=diff 421 4.3.2 VPOP3 SMTP Server access disabled - content scanner problem! This usually happens if the “VPOP3 AV” virus scanner has a problem it can't automatically recover from. This may be a fatal error, or a licencing issue. You can check this on the Settings text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:550_not_permitted?rev=1542192349&do=diff 550/553 Not Permitted error from BT Internet's mail servers BT Internet's mail servers only allow messages to be sent from 'approved' email addresses. If you try to send messages from other addresses BT's mail servers may return a '550 Not Permitted' error, a '553' error, or may silently discard the message depending on what their server feels like doing today. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:11002?rev=1542192349&do=diff Socket Error 11002 - Host not found (Non-Authoritative answer) This means that VPOP3 is not getting a response from a DNS server when it is trying to look up the name of the ISP's mail server(s). Usually this means that Windows either does not know the address of a valid text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:attachments_have_been_removed_or_renamed?rev=1542192349&do=diff Attachments have been removed or renamed If you have received an email and one or more of its attachments have been removed or renamed, it might be a result of Attachment Filtering. You can inspect the filtering rules by going to Administration Settings -> Settings -> text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:c_error_popup?rev=1542192349&do=diff C++ Error Popup If VPOP3 crashes with a C++ error popup window, that means that an 'exception' has been thrown - something unusual has happened, and VPOP3 doesn't know how to recover automatically. Often these are due to database errors. There are two places you can look for the cause of the error: text/html 2026-03-23T10:18:43+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:create_an_ssl_certificate?rev=1774261123&do=diff How to create an SSL Certificate VPOP3 Enterprise supports SSL certificates for encrypted sessions. The basic mechanism to create an SSL certificate is that you have to generate a CSR (Certificate Signing Request) then send that to a CA (Certificate Authority) who will sign your certificate and give you the certificate back. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:daily_summary_does_not_show_all_sent_messages?rev=1542192349&do=diff Daily Summary is not reporting all Sent messages For VPOP3 to log outbound messages it needs to be able to work out that the message is FROM: a user whose mail is handled by the local VPOP3. To do this it has to examine the FROM: address in the message header. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:database_maintenance?rev=1542192349&do=diff Database Maintenance VPOP3 uses the PostgreSQL database server for most of its data storage. Normally this will not require any special maintenance, because it will manage itself. To do any special database maintenance you will need to close down VPOP3 first, because PostgreSQL needs exclusive access to the database to perform any operations such as decreasing the size of database files. Note that these operations may take some time! There are some PostgreSQL utility programs in the VPOP3\pgs… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:delete_a_user?rev=1542192349&do=diff How to Delete a User To delete a user from VPOP3, go to Users -> Accounts, select the user you wish to delete, and press the Delete button. Deleting an administrator You cannot delete the user as whom you are currently logged into the VPOP3 settings (e.g. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:filtering_attachments?rev=1542192349&do=diff How to filter attachments VPOP3 can filter attachments in several ways. The most general is to use the Settings -> Attachment Processing -> Filtering tab as described below. VPOP3 can also filter attachments using the content/spam filter, or by using an integrated virus scanner. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:invalid_helo_name?rev=1542192349&do=diff SMTP error 'Invalid HELO name' When sending mail you may get an error from the remote SMTP server saying something like 'Invalid HELO name' This happens if the host name configured in VPOP3 does not look like a valid Internet host name (e.g. 'mail.domain.com'). Some SMTP servers don't bother checking this value because it has no authentication value at all, but a few do check that it looks correct. text/html 2026-04-06T17:59:47+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:mail_not_downloading_from_isp?rev=1775498387&do=diff Mail Not Downloading From ISP This normally happens because you have told VPOP3 to Leave Messages On Server (on the Mail Connectors -> Mail Collectors -> (name) -> POP3 General tab). If you do this, VPOP3 will leave messages on the ISP's mail server for several days, and remember that it has already downloaded them. Then, the next time it connects it will see that there are some messages waiting, but it may find that it has already downloaded them, so it won't download them again. text/html 2026-04-06T17:57:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:make_vpop3_redownload_messages_from_isp?rev=1775498220&do=diff How to make VPOP3 re-download POP3 messages from the ISP If you have the VPOP3 Mail Collector setting Leave Mail On Server enabled, then VPOP3 will leave your messages on the ISP POP3 server for the specified number of days after downloading it. If, during this time, you want to make VPOP3 download those messages again, then you can do so. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:many_instances_of_postgres.exe_running?rev=1542192349&do=diff Many instances of Postgres.exe are running If you are running VPOP3 3.0 or later, and look in the 'Processes' list in Windows TaskManager you will probably see multiple instances of postgres.exe running. This is perfectly normal, and does not indicate a problem. The PostgreSQL database works by having a separate instance of postgres.exe for each connection to the database (as well as a few extra for management and house keeping). This behaviour is documented on the text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:problem_installing_postgresql?rev=1542192349&do=diff Problems with installing PostgreSQL during VPOP3 Installation Sometimes people have problems with the PostgreSQL installation part of the VPOP3 installation. Below are some things to look at. * Check that 'Local System' (or 'System') has full access to the VPOP3 installation directory text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:rbl_checking_not_working_in_vpop3_enterprise?rev=1542192349&do=diff RBL Checking not working in VPOP3 Enterprise VPOP3 Enterprise has an RBL checking feature which is configured in the VPOP3 Settings at Services -> SMTP Server -> SPAM Reduction -> Realtime Blacklist Rules If it does not seem to be working properly, there are a few reasons why the RBL feature may not work. text/html 2024-01-15T11:35:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:repairing_corrupted_database?rev=1705318545&do=diff Repairing corrupted database With PostgreSQL (as with most high-end databases) the database system will automatically recover after power failures etc, if it can. If it can't then there is no manual 'repair' function, because the data cannot totally be recovered (or it would automatically have been recovered). text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:seeing_where_a_message_came_from?rev=1542192349&do=diff Seeing where a message came from Sometimes you need to check to see where a message really came from. The 'From:' email address is easily forged, so that cannot be relied upon. The first thing you have to do is to get the full message headers. These may look daunting, but are very useful for problem diagnosis. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:spam_filter_content_filter_scripts?rev=1542192349&do=diff Spam filter / Content filter scripts The spam filter system uses basic scripting language for processing messages. This can be used for custom content filtering as well if you need to look inside the messages (e.g. at message content, attachments) as well as at the message headers etc. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_alert_-_non-existent_user?rev=1542192349&do=diff Error message: VPOP3 Alert - Non-existent user - <username> If you receive an error message like: Subject: VPOP3 Alert - Non-existent user - <username> Delivery Failure Report. There was incoming mail for non-existent user "<username>". This means that VPOP3 downloaded a message using POP3 and it was addressed to an email address which does not exist. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:diagnostics?rev=1542192349&do=diff Settings -> Diagnostics The Diagnostics page allows you to enable, configure and disable various methods of diagnostic logging, within VPOP3. Log file overview By default, VPOP3 will keep two copies of most log files: * The current log file, with a text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:download_rules?rev=1542192349&do=diff Download Rules Download rules are a facility in VPOP3 where it can look at message summary information before downloading a message from an ISP POP3 mailbox (they do not work on incoming SMTP messages - use SMTP Rules for that) To edit download rules, go to text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:mail_senders?rev=1542192349&do=diff Mail Connectors -> Mail Senders The Mail Sender tells VPOP3 how to send mail out to the Internet. If you want to send mail for specific users to another specific mail server (e.g. a local Microsoft Exchange Server or another VPOP3 server) then use the text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:mappings?rev=1542192349&do=diff Mappings In VPOP3, Mappings are a way of explicitly linking an email address to a user or list. They can also be used to indicate that an email address is remote, even though it would otherwise appear to be a local email address. In other email servers, a similar feature may be called 'aliases' text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:pop3_collection?rev=1542192349&do=diff POP3 Mail Collection POP3 Mail Collection is when VPOP3 will collect mail from an external POP3 mailbox - for instance, from an Internet Provider. POP3 General This page tells VPOP3 how to collect mail. * POP3 Server Address - this is the name (or IP address) of the POP3 server from which you want VPOP3 to collect mail text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:route_by_parsing_message_headers?rev=1542192349&do=diff Route incoming POP3 mail by parsing message headers This routing method is generally used if you have a catch-all or 'multi-catch' mailbox with your Internet provider. With this method, VPOP3 will look at the To/Cc and other fields in the message headers to try to work out who the message is for. If the recipient is not listed in the headers (eg for BCCd mail) it may not be able to automatically detect who the message is for. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:smtp_advanced?rev=1542192349&do=diff SMTP Service -> Advanced Tab Services -> SMTP Server -> Advanced Tab Refuse SMTP Connections from This setting should be rarely needed, and should be normally left blank. It is here for historic purposes. If you put some text in this box, then VPOP3 will refuse any SMTP connections from clients whose 'HELO'/'EHLO' command data contains the text specified here as a substring. Eg, if this setting is set to '.myisp.com', then VPOP3 would refuse SMTP connections from any client which sends the c… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:spamrules_statement_dns?rev=1542192349&do=diff Spam Filter Rules: DNS Statement DNS Version 2.1.11+ Purpose Allows the script to perform an arbitrary DNS lookup, returning the result into a specified variable The DNS statement requires a type, hostname and variable name, in the format DNS <type> <hostname> <variable name> text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:spamrules_statement_foreach?rev=1542192349&do=diff Spam Filter Rules: ForEach Statement ForEach Version 2.1.7+ Purpose Causes a loop to be run through for all values within specified criteria The ForEach statement requires either two or three parameters (depending on the type of loop that is being conducted), in the format text/html 2024-04-22T08:37:38+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:user_manager_script?rev=1713775058&do=diff User Manager Script If you want people to be able to log in using a different username than their VPOP3 username (eg if you want them to be able to log in using an email address), then you can use the UserManager Lua script The Lua script is managed through the Settings → Scripts page in VPOP3 v8.0 and later and is called 'UserManager.LUA. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/reference:user_message_rules?rev=1542192349&do=diff Message Rules The Edit User -> Message Rules tab can be used to create/edit rules which are processed when messages arrive in a User's mailbox. They can be used to copy messages, mark them as read, delete them, etc VPOP3 will process Message Rules in the order they appear in the list. If you want to change the order of the rules, you can drag & drop them into the correct order. Usually when VPOP3 has processed a rule, it will go on to check further rules, but you can use the text/html 2022-10-01T11:32:39+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/wiki:welcome?rev=1664623959&do=diff Welcome to your new DokuWiki Congratulations, your wiki is now up and running. Here are a few more tips to get you started. Enjoy your work with DokuWiki, -- the developers Create your first pages Your wiki needs to have a start page. As long as it doesn't exist, this link will be red: