https://wiki.pscs.co.uk/ 2026-05-06T11:57:36+00:00 https://wiki.pscs.co.uk/ https://wiki.pscs.co.uk/_media/wiki:dokuwiki.svg text/html 2025-08-18T15:28:11+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:configure_srs?rev=1755530891&do=diff Configure SRS In VPOP3 8.8 and later, you can use Lua scripting to implement 'SRS' (Sender Rewriting Scheme') in VPOP3 This involves adding a couple of functions to rewrite outgoing return paths in 'relayout.lua' or 'mxout.lua' as appropriate and a couple of functions to redirect rewritten bounce message recipients in 'smtpsvr.lua' 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: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:535_authentication_failed?rev=1542192349&do=diff 535 Authentication Failed This is an SMTP error meaning that an attempt to authenticate has failed. If this error is appearing when the email client is trying to log into VPOP3, then you can check the VPOP3 'SECURITY.LOG' file which may contain more information, such as an invalid password, unknown username, etc. (This information is not returned in the SMTP session because it would help an attacker). 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: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: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 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 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 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: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: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 2022-11-18T11:43:52+00:00 Anonymous (anonymous@undisclosed.example.com) https://wiki.pscs.co.uk/how_to:restore_deleted_calendars?rev=1668771832&do=diff Restore Deleted Calendars This article will help if a user has been deleted and all their calendars are lost and need to be restored. Note that this functionality is not built into VPOP3, and requires the use of Python3 to run a script First you need to install Python 3.8 or later, and the psycopg2 plugin 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:smtp_client_problem?rev=1542192349&do=diff VPOP3 - SMTP Client Problem These errors occur whilst VPOP3 is communicating with your ISP's SMTP mail server to send your mail. If the message text is: Error with SMTP Client (XXXX (YY)) The server connection was closed unexpectedly Then this means that the the connection between VPOP3 and your ISP's SMTP mail server was closed when VPOP3 did not expect it to be. This can be caused by the network connection failing or a bug in the ISP's mail server which drops the connection in abnormal circ… 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