HPR3060: Running a local imap server

Setting up a local imap server

To install a local imap daemon that will only listen to localhost connections, made via ssh tunneling. This is for use as a local backup of your imap files, or for keeping a remote backup somewhere.

This is not a mail delivery solution but rather a way to keep a backup of your email using to a MailDir directory that you can access using your email client. As each message is stored in its own file, you can also use normal tools like find|sed|awk|grep to find messages.

This setup can be installed locally or remotely on, for example, a raspberry pi. In that case you can enable a portforwarding rule in ~/.ssh/config to include something like LocalForward 127.0.0.1:2143 127.0.0.1:143

Install using aptitude install courier-imap courier-authdaemon

You can check the status using systemctl status courier-imap.service courier-authdaemon.service

Edit the file /etc/courier/imapd and modify the following settings:

Address to listen on, can be set to a single IP address.

< ADDRESS=0
> ADDRESS=127.0.0.1

Maximum number of IMAP servers started

< MAXDAEMONS=40
> MAXDAEMONS=80

Maximum number of connections to accept from the same IP address

< MAXPERIP=20
> MAXPERIP=40

The following setting is optional, and causes messages from the given folder to be automatically deleted after the given number of days.

< IMAP_EMPTYTRASH=Trash:7
> #IMAP_EMPTYTRASH=Trash:7

Change the directory name of the maildir directory.

< MAILDIRPATH=Maildir
> MAILDIRPATH=/home/pi/MailDir

Then restart the service using systemctl restart courier-imap.service courier-authdaemon.service.

When I did this I got a strange error about but installing the package gamin fixed it. Which is a Library providing the FAM File Alteration Monitor API.

Filesystem notification initialization error -- contact your mail
administrator (check for configuration errors with the FAM/Gamin library)

Links

https://www.courier-mta.org/imap/documentation.html
https://www.faqforge.com/linux/fix-for-courier-imap-error-check-for-configuration-errors-with-the-famgamin-library/