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 user 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 user 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 Recipients Per Mail - This restricts the maximum number of recipients per mail during a mail transfer. This is a simple security restriction which helps prevent abuse of the POP3 retrievals.
• 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 'Max Mails Per Connection' option is enabled, connections which close due to the max mail limit being reached will immediately reconnect and continue. If disabled, the remaining mails will only be downloaded when the POP3 retrieval is re-triggered.
• 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 original sender.
• Add Received Header Line - If enabled, all mails that are retrieved will have a received header line inserted.
• Hide IP in Received Header Line - If enabled, POP3 retrievals will not print the senders IP address in the received line at the top of the mail header. This is useful if you wish protect against exposing your users IPs to the receivers of their mail.
• Insert 'for' Field into Received Header Line - If enabled, the POP3 Retrieval service will print the first recipient into the received line using the 'for' field.
• Enable Bayesian SPAM Filtering - If this option is enabed, all mail will be scanned with the Bayesian SPAM filter.
• Block Mail if SPAM Detected - If this option is enabled and the Bayesian SPAM filter is triggered, POP3 retrievals will block mails before they even enter the mail server. This is the strongest method of enforcing SPAM protection. This option allows the use of field tags. For more information please view the Tutorial: Using Field Tags page.
• Send Failure Message - If the mail is blocked due to the Bayesian SPAM filter triggering, this option allows a failure message to be generated and sent to the original sender. Caution must be used when enabling this option as very often SPAM mails spoof the address that the mail was sent from. Therefore, sending a failure to the apparent sender may actually send the failure to someone that never sent the mail. Doing this could actually be seen as your mail server sending SPAM.
• Set SPAM Flag - If this option is enabled and the Bayesian SPAM filter is triggered, the mail’s SPAM flag will be set. Content Filtering or any account filtering rules can then process the mail accordingly.
• Add Custom Event - If this option is enabled and the Bayesian SPAM filter is triggered, the string will be appended to mail's custom event list. These custom events can then be read using Content Filtering, which allows more complex actions to be performed on the mail.

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 that 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 ‘if Possible’ type option from the list. This will cause outbound connections to try the SSL method but if that fails they will revert to the normal connection.
• Test POP3 Retrieval - This will perform tests to ensure that mail can be retrieved successfully using the settings provided.
• Deliver To - This is a list of email addresses that the POP3 retrieval will try to deliver any new mail to. 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.
• Deliver To All Header Line Recipients - If enabled, the POP3 retrieval will try to deliver any new mail to all To, Cc and Bcc header line recipients from the mail header. 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.
• 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' is enabled.