https://wiki.pscs.co.uk/ 2026-05-06T11:51:00+00:00 https://wiki.pscs.co.uk/ https://wiki.pscs.co.uk/_media/wiki:dokuwiki.svg text/html 2021-03-08T10:48:40+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:install_vpop3?rev=1615200520&do=diff How to Install VPOP3 Simply download VPOP3 from the website, and run the installation program and follow the prompts. Occasionally people may have problems with the PostgreSQL part of the installation. If that happens, please contact us either by email at support@pscs.co.uk or by phone to +44 (0)1484 855800, and we will do our best to help. 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: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 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 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:database_disk_caching?rev=1542192349&do=diff Database & Disk Caching Disk Caching One key point is that, like all other high-end databases, PostgreSQL should not be run on a server with disk level write back caching. With write back caching, the disk will report data as being written to disk when it is still in the disk's cache memory. If the power then fails, this data is lost and can cause database corruption. As long as the database server really knows when the data has been written to disk, power failure will not cause database corru… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:installation_conflicts?rev=1542192349&do=diff Installation conficts During installation, the installer program does some basic checks for conflicting software. This is software which is providing the same services as the VPOP3 software - i.e. SMTP, POP3 and/or LDAP services. For POP3/SMTP it will show the text which the conflicting software announces itself as. 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: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:timeout_problems_when_sending_or_receiving_attachments?rev=1542192349&do=diff Timeout problems downloading/uploading messages with attachments There are various possible reasons for this, usually to do with third party internet security software but they may also be associated with Windows TCP/IP or dial-up adapter issues. You may not have problems with other software, but that doesn't mean the problem is being caused by VPOP3. text/html 2019-11-12T16:09:08+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:v3_-_move_to_a_new_pc?rev=1573574948&do=diff Move VPOP3 Version 3 or 4 to a new PC Moving VPOP3 Version 3 or 4 to a new PC is slightly different from moving earlier versions, because of the database system. The summary of steps is: * Stop VPOP3 on the original PC * Manually make a backup of the database on the original PC text/html 2026-04-21T11:12:40+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:v5_-_move_to_a_new_pc?rev=1776769960&do=diff Move VPOP3 Version 5 (or later) to a new PC Moving VPOP3 Version 5 or later to a new PC is slightly different from moving earlier versions, because of the database system, which was introduced for version 3 and modified for version 5. The summary of steps is: * Stop VPOP3 on the original PC 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_too_many_connections_from_your_ip_address_-_try_later?rev=1542192349&do=diff 421 4.3.2 VPOP3 Too many connections from your IP address - try later If you see this error message when you are sending messages, then it means that VPOP3 has detected too many simultaneous connections from your IP address. This would usually happen if the sender is another mail server as they can make many simultaneous connections when there are lots of messages to send. The error code that VPOP3 gives means that the sender should try sending the messages later, so it should be possible to e… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:550_5.7.1_unable_to_relay_for?rev=1542192349&do=diff 550 5.7.1 Unable to Relay for... When trying to send emails from your email client software you get an error in your email client 550 5.7.1 Unable to relay for ... This error is happening because you have installed the Microsoft IIS SMTP Service, and your email client is talking to that service rather than to VPOP3. 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:10061?rev=1542192349&do=diff Socket Error 10061 - The attempt to connect was forcefully rejected Error 10061 means that the computer which VPOP3 was trying to connect to (probably at your ISP) refused the connection from the computer running VPOP3. There are several possibilities that can cause error 10061: text/html 2025-05-21T07:57:18+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:allowing_mail_relay_through_vpop3?rev=1747814238&do=diff How To Allow Mail Relay Through VPOP3 If you are allowing remote access into VPOP3 to collect mail then you may also want those remote users to be able to send their outgoing mail through VPOP3 as well. This is more complex than allowing users to collect mail, because, by default, SMTP connections are not authenticated. This means that when someone tries to send a message through VPOP3, VPOP3 doesn't know who that user is. This can cause a problem if unauthorised users try to send mail through… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:backscatter?rev=1542192349&do=diff Backscatter In email, “backscatter” is the term used if you send bounce messages back to spam messages. As most spam messages use forged email addresses, then the bounce messages will go to an innocent person, who will find them very annoying. Stopping VPOP3 from sending Backscatter 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 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:calendar_on_ios?rev=1542192349&do=diff Configuring Calendar on iOS These instructions are for configuring a new Calendar account on iOS for iPhone, iPad and iPod Touch. The version of iOS used for these instructions is iOS v6.0, but they will probably work or help with other versions of iOS. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:error_message_handling?rev=1542192349&do=diff Error Message Handling VPOP3 will normally send an error message to the Main Administrator every time it encounters an error. We recommend you leave it like this in most cases - if an error message occurs repeatedly, then it usually means there's an underlying problem which needs resolving rather than ignoring. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:exchange_2007?rev=1542192349&do=diff Exchange 2007 You can link VPOP3 to Exchange Server, so that Exchange Server sends outgoing mail through VPOP3 and VPOP3 sends any incoming mail directly to Exchange Server. You should first of all set up VPOP3 to send and receive Internet email as normal. 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:out_of_disk_space_when_sending_mail?rev=1542192349&do=diff Out of Disk Space When Sending Mail The first thing you should do is check that there is enough free disk space on the disk where VPOP3 is installed. VPOP3 requires a certain amount of free space before it will allow new messages to be sent, so the disk might not be totally full, but VPOP3 will still report that there is insufficient disk space when you try to send a new message. This buffer zone is designed to help prevent the disk totally filling up, which can cause lots of bigger problems! text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:outlook_not_able_to_connect_to_vpop3_enterprise_v6.8_when_using_ssl_tls?rev=1542192349&do=diff Outlook not able to connect to VPOP3 Enterprise v6.8 when using SSL/TLS In VPOP3 6.8 SSL v2 is disabled by default (it is considered to be insecure). SSL v3 was released in 1996 and SSL v2 was deprecated because of the well known security flaws. However, it seems that Microsoft Outlook (up to at least Outlook 2010) will not connect to VPOP3 using SSL if VPOP3's SSL v2 is disabled. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:postgresql_server_won_t_start_due_to_damaged_log_files?rev=1542192349&do=diff PostgreSQL server won't start due to damaged log files If the PostgreSQL server won't start at all, because its transaction logs are damaged, you will probably need to recreate the database store totally. To rebuild the database: * Open a command prompt and find the VPOP\pgsql folder 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: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:sender_domain_must_resolve?rev=1542192349&do=diff Sender Domain Must Resolve If you receive an 'SMTP Client Error' something like: 451 (user@domain.com) Sender Domain Must Resolve this means that the ISP's mail server cannot find the domain.com part of the email address. Often this means that the FROM address of the message is invalid, or that the text/html 2020-07-22T10:32:40+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:signing_outgoing_mail_with_dkim?rev=1595413960&do=diff Signing outgoing mail with DKIM DKIM, also known as DomainKeys Identified Mail, is a form of email authentication that digitally signs emails to prove that they were sent from authorized domains and aren't fake emails. Companies like Google and Yahoo use DKIM to sign their emails and it is becoming ever more popular. 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:upgrade_vpop3?rev=1542192349&do=diff How To Upgrade VPOP3 Note: if you are upgrading to VPOP3 version 5 or later from version 4 or earlier, please see How To Upgrade VPOP3 to version 5 Upgrading VPOP3 is a straightforward process. Download VPOP3 from our web site and ideally back up your current installation just in case something goes wrong. Then simply run the installer that you downloaded and install it over the top of your existing VPOP3. All your settings and mail will be preserved. 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 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:using_a_mobile_phone_with_vpop3?rev=1542192349&do=diff Using a Mobile Phone with VPOP3 Many people want to use a mobile phone to send/receive their email nowadays. This is usually easy to do with VPOP3. The recommended way is to have the phone connect directly to VPOP3 for sending/receiving email. To do this, you need to do three things: 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_cannot_access_postgresql_-_timeout_expired?rev=1542192349&do=diff VPOP3 cannot access PostgreSQL - timeout expired This is an error which may be logged in the Windows event log It is event 4547 from the source 'VPOP3' If the event message DLL is not correctly installed it may display as: The description for Event ID ( 4547 ) in Source ( VPOP3 ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this desc… text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_deleting_messages_as_old_messages?rev=1542192349&do=diff VPOP3 Deleting messages as 'old' messages If VPOP3 says 'deleting old message' in the status window activity log that means that it has seen the unique ID of that message before, longer ago than the time specified for VPOP3 to leave messages on the server, so it thinks that the message is an old message, and so deletes it. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_is_responding_slowly?rev=1542192349&do=diff VPOP3 Is Responding Slowly If VPOP3 is responding slowly to users there are several common causes: * The VPOP3 server disk may be badly fragmented. Defragment the server disk(s). Note that sometimes the Windows defragmenter will say that the disk doesn't need defragmenting even if it does, so it is best to do it anyway. Also, there is a better free defragmenter available called text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:vpop3_not_starting_properly?rev=1542192349&do=diff VPOP3 Not Starting Properly If VPOP3 is not starting properly, then the first thing to check is whether the database server is starting. In VPOP3 v3 and later, VPOP3 uses a PostgreSQL Database server for data storage, so if the database server is not running, VPOP3 will not be able to start properly. In this case, the VPOP3.EXE process may appear in Task Manager, but it won't respond to anything, or it may appear in Task Manager and then stop after a short period. text/html 2018-11-14T10:45:49+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:when_sending_mail_vpop3_adds_prvs_.._to_the_sender_address?rev=1542192349&do=diff When sending mail, VPOP3 adds 'PRVS=...' to the sender address This is because VPOP3 version 5 and later support BATV. BATV helps to eliminate 'backscatter spam', where someone else sends spam pretending to be from you, and then you receive all the bounce messages from those messages. BATV encodes the sender address in a special way so that VPOP3 can detect that a bounce message is in response to a message that you actually sent. 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 ->