14.6. Integration of Fetchmail for retrieving mail from external mailboxes

Usually, the UCS mail service accepts mails for the users of the UCS domain directly via SMTP. UCS also offers optional integration of the software Fetchmail for fetching emails from external POP3 or IMAP mailboxes.

Fetchmail can be installed via the Univention App Center; simply select the Fetchmail application and then click on Install.

After the installation, the Advanced settings ‣ Remote mail retrieval (single) and Remote mail retrieval (multi) tabs in the user administration provide additional input fields. Use them to configure the retrieval of emails from a remote mail server.

Fetchmail delivers emails to the inboxes of the corresponding users. The user account must have the primary email address configured for this. Before using multi-drop configurations, read THE USE AND ABUSE OF MULTIDROP MAILBOXES in the Fetchmail manual.

The mail is fetched every twenty minutes once at least one email address is configured for mail retrieval. After the initial configuration of a user Fetchmail needs to be started in the UMC module System services. In that module the fetching can also be disabled (alternatively by setting the Univention Configuration Registry Variable fetchmail/autostart to false).

Table 14.3 Remote mail retrieval (single) tab

Attribute	Description
Username	The username to connect to the email server for fetching emails.
Password	The password for the user to connect to the email server for fetching mail.
Protocol	The protocol that Fetchmail uses for fetching emails. Choose either IMAP or POP3.
Remote mail server	The hostname of the email server that Fetchmail uses to fetch emails.
Use SSL	This option enables encrypted mail fetching. For it to work, this feature has to be supported by the mail server.
Keep mail on remote server	By default, Fetchmail deletes fetched email from the remote server after the transfer. To keep the emails on the remote server, enable this option.

Table 14.4 Remote mail retrieval (multi) tab

Attribute	Description
Username	The username to connect to the email server for fetching emails.
Password	The password for the user to connect to the email server for fetching mail.
Protocol	The protocol that Fetchmail uses for fetching emails. Choose either IMAP or POP3.
Remote mail server	The hostname of the email server that Fetchmail uses to fetch emails.
Local Domain Names	A space-separated list of local domain names. Leave it empty to use all local domains.
Virtual qmail prefix	Fetchmail removes the defined string prefix from the email address found in the header specified with the envelope header option. For example, if the value is example-prefix- and Fetchmail retrieves an email whose header matches an address such as example-prefix-info@remotedomain.com, Fetchmail forwards the email as info@localdomain.com.
Envelope Header	The value of this field sets the header that Fetchmail expects to appear as a copy of the mail envelope address. Fetchmail uses it for mail rerouting.
Use SSL	This option enables encrypted mail fetching. For it to work, this feature has to be supported by the mail server.
Keep mail on remote server	By default, Fetchmail deletes fetched email from the remote server after the transfer. To keep the emails on the remote server, enable this option.