POP3 Retrievals

This service allows you to retrieve mail from other mail servers and deliver them into one or more local accounts. This is useful for centralizing mail from multiple locations into one place, making it easier for users to check their mail.

POP3 Retrievals

  • Enable POP3 Retrievals - This controls whether the service is enabled.
  • Max Outbound Connections - This controls the maximum number of simultaneous connections the service will allow. It is recommended that this value be no higher than 200. If the all available connections are being used, further requests will be placed in a queue.
  • Max Queue Size - This controls the maximum number of requests that can be placed into the queue to wait for an outbound connection to become available. If the queue is full, further requests will be discarded. In WebMail an appropriate error message will be shown. In other cases, the request will be silently deleted.
  • Max User Retrievals Per Day - This controls the maximum number of POP3 Retrieval triggers per day. These triggers can be either manual triggers performed via WebMail or triggers caused by service logins. All triggers can be restricted in the Group settings.
  • Max User Retrievals Per IP Per Day - This controls the maximum number of POP3 Retrieval triggers per IP per day. These triggers can be either manual triggers performed via WebMail or triggers caused by service logins. All triggers can be restricted in the Group settings.
  • Max Hop Count - Often mail servers may be configured in such a way that they accidentally form mail loops which can cause a mail to jump between two mail servers indefinitely. This option helps prevent mail loops by setting a limit on the number of hops allowed.
  • Send Hop Count Failure Message - If the hop count level is triggered, this option allows a failure message to be generated and sent to the 'From' address.
  • Max Mails Per Connection - If enabled, each connection will limit the number of mails downloaded. This helps reduce the receiving of multiple copies of the same mail if the connection is interrupted.
  • Reconnect Immediately if Max Reached - If enabled and the If enabled, each connection will limit the number of mails downloaded. This helps reduce the receiving of multiple copies of the same mail if the connection is interrupted. option is enabled, then connections which close due the max mail limit being reached will immediately reconnect and continue. If disabled, then the remaining mails will only be downloaded when the POP3 Retrieval is re-triggered.
  • Convert Bare LFs into CRLF Pairs During Mail Transfer - If enabled, any bare LF characters received during the mail transfer will be converted into a CRLF pair. Although this option shouldn't require enabling, some poorly constructed HTML mails can often be truncated due to the use of bare LFs.
  • Add Received Header Line - If enabled, all mails that are retrieved will have a 'Received' header line inserted.
  • Insert 'for' Field into Received Header Line - If enabled, the POP3 Retrievals service will print the first recipient into the received line using the 'for' field.

SPAM Filtering

  • Enable SPAM White List for Mails Received by Automatic POP3 Retrievals - If enabled, all mails retrieved by Automatic POP3 Retrievals will be passed through the SPAM White List. If the SPAM White List is not enabled, this setting is ignored.
  • Enable SPAM White List for Mails Received by Per User POP3 Retrievals - If enabled, all mails retrieved by user triggered POP3 Retrievals will be passed through the SPAM White List. If the SPAM White List is not enabled, this setting is ignored.
  • Enable SPAM Black List for Mails Received by Automatic POP3 Retrievals - If enabled, all mails retrieved by Automatic POP3 Retrievals will be passed through the SPAM Black List. If the SPAM Black List is not enabled, this setting is ignored.
  • Enable SPAM Black List for Mails Received by Per User POP3 Retrievals - If enabled, all mails retrieved by user triggered POP3 Retrievals will be passed through the SPAM Black List. If the SPAM Black List is not enabled, this setting is ignored.
  • If SPAM Black List Refuses the Mail: Silently Delete Mail - If set and the SPAM Black List refuses the mail, the mail will be silently deleted without notice.
  • If SPAM Black List Refuses the Mail: Send Failure Message - If set and the SPAM Black List refuses the mail, the mail will be deleted and a failure notice will be sent to the 'From' address.
  • Enable Bayesian Filtering of Mails Received by Automatic POP3 Retrievals - If enabled, all mails retrieved by Automatic POP3 Retrievals will be passed through the Bayesian Filter. If the Bayesian Filter is not enabled, this setting is ignored.
  • Enable Bayesian Filtering of Mails Received by Per User POP3 Retrievals - If enabled, all mails retrieved by user triggered POP3 Retrievals will be passed through the Bayesian Filter. If the Bayesian Filter is not enabled, this setting is ignored.
  • If Bayesian Filter Refuses the Mail: Silently Delete Mail - If set and the Bayesian Filter refuses the mail, the mail will be silently deleted without notice.
  • If Bayesian Filter Refuses the Mail: Send Failure Message - If set and the Bayesian Filter refuses the mail, the mail will be deleted and a failure notice will be sent to the 'From' address.

Automatic POP3 Retrievals

  • Poll Frequency - This controls how often Automatic POP3 Retrievals are performed.
  • POP3 Retrievals - This is a list of all Automatic POP3 Retrievals which will be triggered at the interval specified by the Poll Frequency.

Add / Edit POP3 Retrieval

  • Enable POP3 Retrieval - This controls whether the POP3 Retrieval is enabled.
  • Host - This controls the host name that will be used for the connection. This must be the host name of a mail server which the POP3 Retrieval will try to retrieve mail from.
  • Port - This controls which port on the host mail server will be used for the connection. This must match the POP3 port value used on the host mail server. The default POP3 port value of 110 is normally used.
  • User - This controls the username that will be supplied when trying to log into the host mail server. This must match a valid account username on the mail server.
  • Password - This controls the password that will be supplied when trying to log into the host mail server. This must exactly match the password for the specified user on the host mail server.
  • Destination Folder - This is the folder which new mail will try to be placed in for each of the delivery accounts. If the folder does not exist for any of the accounts, any new mail will be placed in the Inbox folder instead.
  • SSL Mode - This option controls the use of SSL and TLS. Some POP3 servers may support SSL but if not this option should be set to 'None'. If you are not certain that SSL will be supported but still wish to try anyway, you can select an SSL mode from the list. This will cause outbound connections to try to use SSL.
  • Only Allow Secure Connections - If SSL Mode is set to any SSL mode other than 'None', this option controls whether or not non-SSL connection attempts are allowed when SSL connections fail.
  • Test POP3 Retrieval - This will perform tests to ensure that mail can be retrieved successfully using the settings provided.
  • Leave a Copy of Mails on the Server - If enabled, the POP3 Retrieval will leave a copy of the mails on the server. Subsequent retrievals will ignore previously downloaded mails.
  • Delete After (days) - This allows you to automatically delete any mails stored on the server when they are a certain number of days old. This option is useful for preventing the remote account from endlessly filling with mails, which would also eventually lead to its allocation limit being reached.
  • Delete If Number of Mails Exceeds - This allows you to automatically delete any mails stored on the server when the number of mails stored exceeds this value. This option is useful for preventing the remote account from endlessly filling with mails, which would also eventually lead to its allocation limit being reached.
  • Always Deliver to Addresses - Any mails retrieved will always be delivered to these email addresses. For local email addresses, new mail will be delivered to the appropriate accounts. For non-local email addresses, the mail will flow into the Outgoing Mail queue to be sent back onto the Internet for delivery to another mail server.
  • Enable Mail Header Delivery - If enabled, any mails retrieved will be re-delivered to email addresses found in the mail's header. This option is useful when downloading mail from a catch-all account and re-delivering to locally stored accounts. For local email addresses, new mail will be delivered to the appropriate accounts. For non-local email addresses, the mail will flow into the outgoing mail queue to be sent back onto the Internet for delivery to another mail server.
  • Only Deliver to Addresses For Domains - This is the list of permitted email addresses that can be used for re-delivery. This also allows you to rename the domain in the email addresses to other domains.
  • Use Header(s) - This option specifies which mail headers to parse when extracting the list of addresses. To set multiple headers, simply separate each with a semi-colon (';').
  • Ignore Addresses for Non-Existent Users - If enabled, any mail header address found will only be used if it exists locally. This option should normally be disabled when the Domain option 'Do Not Try to Relay Mails Addressed to Non-Existent Users' is enabled.