https://wiki.pscs.co.uk/ 2026-05-13T09:51:02+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:10054?rev=1542192349&do=diff Socket Error 10054 - The virtual circuit was reset by the remote end Error 10054 means that the connection between VPOP3 and a remote computer (eg the ISP or another computer on your LAN) was disconnected by something outside of VPOP3. This is often caused by anti-virus software or Internet security/firewall on the VPOP3 machine but it could be any of a number of things. Any software or hardware that is sitting between VPOP3 and the ISP could be the root cause. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:data_stream_contained_nul_character?rev=1542192349&do=diff Data stream contained NUL character Description of the problem NUL characters (bytes with value 0) are not allowed in email messages and should not be transmitted over POP3, SMTP or IMAP4 except in certain circumstances. If an attachment contains such a byte it must be encoded using text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:backup_vpop3?rev=1542192349&do=diff How to Backup VPOP3 By default VPOP3 v3 and later will automatically perform a daily backup of the database into a file called DBBACK-x.DMP, where the backup file rotates on a weekly basis (DBBACK-0.DMP is Sunday's backup, DBBACK-1.DMP is Monday's backup, etc). text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:delete_outqueue_messages_directly_from_the_database?rev=1542192349&do=diff Delete OutQueue messages directly from the database If there is an extremely large number of messages (eg hundreds of thousands) in the VPOP3 OutQueue, then it may take a very long time for VPOP3 v5 and later to start as it check the message database tables for consistency during initialisation. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:forwarded_emails_not_arriving?rev=1542192349&do=diff Forwarded Emails Not Arriving If you are having problems having VPOP3 forward incoming messages to an external address, but sending messages directly to that address works OK, and forwarding internal messages to that address works OK, then the problem may be the SMTP return address which VPOP3 is using. 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:pop3_client_problem?rev=1542192349&do=diff VPOP3 - POP3 Client Problem These errors occur whilst VPOP3 is communicating with your ISP's POP3 mail server to retrieve your mail. The server connection was closed unexpectedly If the message text is Error with Pop3 Client (XXXX (YY)) The server connection was closed unexpectedly 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/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:552_5.2.3_message_too_large_-_contact_your_administrator?rev=1542192349&do=diff 552 5.2.3 Message too large - contact your administrator Or 552 5.2.3 Message exceeds fixed maximum message size If this error message is coming from VPOP3 when you are sending a message, it means that the message you are sending is prohibited by your VPOP3 settings. There are two places where the size limit could be set. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:10048?rev=1542192349&do=diff Socket Error 10048 - Specified Address Already in Use This error only normally occurs during VPOP3 startup. It occurs if some other software running on the same machine as VPOP3 is using one of the ports that VPOP3 is already using. This could be a proxy like WinGate, WinProxy or anti-virus software that acts as a proxy, an LDAP server (e.g. Active Directory) or another mail server program (e.g. Exchange Server). The latter two causes are particularly common on text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:10053?rev=1542192349&do=diff Socket Error 10053 - An established connection was aborted by the software in your host machine. Error 10053 means that an established connection has been dropped. There are three descriptions of this error message we know about, but the descriptions are given by Windows, so they may vary depending on your version of Windows: text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:11001?rev=1542192349&do=diff Socket Error 11001 - Host not found (authoritative answer) This means that the ISP POP3 or SMTP server which you have told VPOP3 to connect to does not currently exist. This might be that you have mistyped the server address, or that your ISP is having temporary problems, or that you are using an internal text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:android_-_stock_client?rev=1542192349&do=diff Android - Stock Client Warning If you use the stock email client from Android 4.x, then be VERY careful if you are using POP3 download. It appears that the stock client will download all the messages from your mail server every time it checks for mail, so you could use a text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:archiving_not_saving_messages_on_a_shared_drive?rev=1542192349&do=diff Archiving not saving messages on a shared drive If the VPOP3 archive facility is reporting “Possible error accessing main store directory” and the archive store directory is a drive on another network computer, then there are a few possible difficulties that you have to be aware of. 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:calendars?rev=1542192349&do=diff Calendars To use the calendar facility in VPOP3 you need a CalDAV aware client. We have tested it with the free Mozilla Sunbird & Lightning products as well as the emClient email client. These products need a URL to be able to access the CalDAV data store. Once you have the URL (see below), copy it into the 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 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:custom_filtering_incoming_mail?rev=1542192349&do=diff Custom filtering incoming mail If you want to filter incoming mail using custom rules there are a few ways of doing this, depending on your exact requirements. * Download rules - if your incoming mail is via POP3 collection, you want to filter on headers, size etc (not contents) 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:handling_mail_for_multiple_incoming_domains?rev=1542192349&do=diff Handling mail for multiple incoming domains VPOP3 can easily handle mail for several incoming domains. Exactly how you do it depends on the exact situation. All domains are 'aliases' If the domains are aliases of each other, for instance, you have 'mycompany.com' and 'mycompany.org', both of which are the same, so each address at mycompany.com also exists at mycompany.org, and the emails go to the same people regardless of which domain is used, then you simply configure the domains in the ma… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:ical_on_mac_osx?rev=1542192349&do=diff Configuring iCal on Mac OSX to connect to VPOP3's CalDAV service This requires VPOP3 v6 or later. The following instructions are for Mac OS X v10.7.5 but should work with similar versions. We have not been able to create an account by going to System Preferences text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:installation_errors?rev=1542192349&do=diff Installation Errors This page lists some errors which may occur during installation and the solution. In general, do NOT 'ignore' any errors unless we tell you to. If you have to retry an installation, when it is an upgrade from versions 1 - 4 going to version 5 or later, then make sure you have told the installer to install the database. Sometimes a partial installation will make the installer think that the database is already installed. 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:non-administrator?rev=1542192349&do=diff Trying to perform administrative tasks without rights This problem can have two symptoms: * When trying to access the VPOP3 settings you get an error “You are trying to perform an VPOP3 administration task while logged in as a non-administrator text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:outlook_2007?rev=1542192349&do=diff How to configure Outlook 2007 Email SMTP Authentication To set up SMTP authentication in Outlook 2007, if your VPOP3 requires it, go to Tools -> Account Settings, select your email account and press Change.... Then, press the More Settings... button text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:outlook_2010?rev=1542192349&do=diff How to configure Outlook 2010 In many ways, configuring Outlook 2010 is a similar to configuring Outlook 2007. The biggest difference you are likely to notice is the new “Ribbon” interface, in place of the traditional menu bar (File, Edit, View, etc.) Email text/html 2019-02-06T17:10:31+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:postgresql_replication?rev=1549473031&do=diff PostgreSQL Replication PostgreSQL 9.1 (used in VPOP3 5 and later) supports replication from a 'Master' to a 'Slave' database server. This can be used with VPOP3 for having a near-realtime backup of your settings & messages. To use the replication, you need to have a file share which is accessible from both PCs. The thing to watch out for is that the PostgreSQL services may be running as a different user from the currently logged in user, so make sure that the user(s) which the PostgreSQL servi… text/html 2025-09-11T13:48:07+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:recovering_messages_from_corrupted_database_into_fresh_database?rev=1757598487&do=diff Recovering messages from corrupted database into fresh database If the VPOP3 message database is corrupted, then one option is to build a fresh database and restore the settings into it, then recover the messages from the old database using the 'Message Restore' function in VPOP3. This has minimal downtime, but old messages will not all be available until the restore has completed. New messages will be available quickly, and you will be able to send messages. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:redirect_message_for_a_user_if_the_sender_is_a_particular_email_address?rev=1542192349&do=diff Redirect message for a user if a sender is a particular email address Say you want messages addressed to 'user1' to be redirected to 'user2' if they came from customer@domain.com This is an unusual requirement, so there is no way to do it in VPOP3. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:remove_messages_from_the_outbound_queue?rev=1542192349&do=diff How to remove messages from the outbound queue To delete messages from the VPOP3 'OutQueue': * log into the VPOP3 settings * go to the Users page * click on the OutQueue entry in the accounts list. This will show you a list of all the messages waiting to be sent by VPOP3 text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:require_smtp_authentication?rev=1542192349&do=diff Require SMTP Authentication There are some situations where VPOP3 needs to know who is sending mail. This may be if you have VPOP3 configured to behave differently depending on who is sending messages - eg if you have different message size limits depending on the sender, or if you have message monitoring configured for certain users, or you don't want certain people to be able to send mail at all. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:restore_folder_-_v5?rev=1542192349&do=diff Restore selected mail folders or mailbox in VPOP3 v5 or later (This option is only available in VPOP3 Enterprise) First - if the problem is that messages were deleted very recently (the default is within 3 days), you can probably use the Undelete feature in VPOP3. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:restricting_number_of_email_recipients_sent?rev=1542192349&do=diff Restricting the number of recipients sent to Some ISPs set restrictions on the number of recipients that you are allowed to send in a certain time period, eg 50 messages per hour, or the number of recipients that you are allowed to send per message or per connection. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:restricting_number_of_messages_sent?rev=1542192349&do=diff Restricting the number of messages sent Some ISPs set restrictions on the number of messages that you are allowed to send in a certain time period, eg 50 messages per hour, or the number of messages that you are allowed to send per connection. Restriction of messages per connection text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:router_problem?rev=1542192349&do=diff Router Problem error messages If you get an error message to the VPOP3 administrator with subject Router Problem and text Local Distribute to <username> Failed Error: Database Error "ERROR: could not open file "base/<number>/<number>": Permission denied" 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:software_conflicting_with_database?rev=1542192349&do=diff Software conflicting with database service We strongly recommend that virus scanners exclude the VPOP3\pgsql\data folder and all subfolders. If a virus scanner decides to quarantine a file from within this folder structure, that can cause VPOP3 not to run, and could lead to data loss or corruption. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:the_message_could_not_be_loaded._please_return_to_the_quarantine_page_and_try_again?rev=1542192349&do=diff The message could not be loaded. Please return to the Quarantine page and try again This error normally means the message file has been deleted from the hard disk (probably by a virus scanner or something else on the PC). If you can find the message in the VPOP3 settings (Settings text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:too_many_logins?rev=1542192349&do=diff "Too many logins" error message VPOP3 version 4 and later have a limit on the number of concurrent logins which can be received for a single user or from a single IP address. This is to prevent a single user from bringing the server down. The current default limits are 20 per user, or 1000 per IP address (to allow multiple people sharing a NAT IP address) text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:total_rebuild_of_database?rev=1542192349&do=diff Total Rebuild of Database If you suspect database corruption, sometimes the best thing to do is to totally rebuild the database. This involves six steps: * Stop VPOP3 * Backup Database * Delete Database * Re-create Database * Restore/Create Database text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:transmission_receipt?rev=1542192349&do=diff Transmission Receipt Message This is not an error message, but we are listing it here because it confuses some people. VPOP3 sends a 'Transmission Receipt' when a message is sent out, and it contains a header asking for the receipt. The default configuration is that it will send the transmission receipt if the sender asks for a read receipt. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_2.x_crashes_when_user_tries_to_download_mail?rev=1542192349&do=diff VPOP3 2.x crashes when user tries to download mail If VPOP3 2.x crashes when a user tries to download mail, there are a few possible causes we know of: * A virus scanner or Internet security software is interfering with the connection between VPOP3 and the email client and is either terminating VPOP3 deliberately, or is blocking VPOP3 causing another part of it to crash text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_access_security?rev=1542192349&do=diff How To Setup VPOP3 Service Security VPOP3 can be configured to restrict access to its various services depending on the client computer's IP address. This is useful if you want to allow access from only certain IP addresses (eg within your LAN) and prevent access from other IP addresses (eg the Internet). text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_historical_logger_backlog?rev=1542192349&do=diff VPOP3 Historical Logger Backlog This problem is primarily related to VPOP3 versions 2.5 -> 2.6. Theoretically it could happen on later versions, but would be extremely unusual (see the note at the bottom if you are using version 3.0 or later) You get an error message with subject text/html 2026-01-05T09:31:47+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_re-downloading_old_messages_from_isp_pop3_server?rev=1767605507&do=diff VPOP3 re-downloading old messages from the ISP POP3 server If you tell VPOP3's POP3 mail collector to leave messages on the ISP's server for a few days, you may find that sometimes VPOP3 will redownload all the messages from the ISP mailbox again. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3db_service_doesn_t_exist?rev=1542192349&do=diff VPOP3DB Service doesn't exist If VPOP3 v3 or later won't start, and you find that the VPOP3DB (or PostgreSQL-VPOP3) service does not exist in the Windows Services list, it may be that you have just moved VPOP3 and made a mistake following the move procedure or something has removed the service for some reason. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:what_is_the_best_practice_to_delete_old_messages_from_the_vpop3_archive_folder?rev=1542192349&do=diff What is the best practice to delete old messages from the VPOP3 archive folder? You should use the 'Offline' tab in the VPOP3 Message Archive settings to tell VPOP3 to move old messages into a ZIP file. You can then store this ZIP file somewhere safe in case you need to refer to it in the future. (If you know you won't want to ever refer to these old messages, you could just delete the ZIP file, but storage costs nowadays are so cheap, we'd recommend keeping it, just in case). text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:write_your_own_spam_filter_rules?rev=1542192349&do=diff How to write your own spam filter rules VPOP3's spam filter uses a basic scripting language designed for filtering email messages, so a full description of writing your own rules would be very long and complex, as it is really something that only a programmer should do.