Mail Server for Linux which can forward Gmail

Question

I have an old computer which I'd very much like to be able to use with my modern Gmail and iCloud email accounts. The old computer can do IMAP, POP and SMTP - but it can't do SSL (hence the need for an intermediary). I can hear the objections already - if you have a new computer, why would you want to use your old one? I'm afraid to say that the answer is 'I just do!'

One of my newer computers, the one that's on all the time, is a Raspberry Pi running Raspbian (a Debian Linux fork). So my question is, is there any software available which can be set up easily and which will act as a mail server for my old computer? It should handle the secure sign in to my email accounts, and then serve that email (Preferably IMAP, but POP is okay too) so that my old computer can retrieve it.

Conversely, when email is sent from my old computer the software should then forward it on to iCloud or Gmail (or whatever).

I've tried using stunnel, but I can't get it to work for me.

Any suggestions will be eagerly received - and I'm sure that I'm not the only person who'd be interested!

Look at https://samhobbs.co.uk/raspberry-pi-email-server for information on how to make raspberry pi a mail server based on raspbian, postfix and dovecot. — ridgy, Feb 04 '17 at 16:12
It's an interesting suggestion - but this doesn't solve the problem of wanting to format from my existing email accounts - this only works if I want to create entirely new email addresses. — headbanger, Feb 04 '17 at 16:21
Another thread that might help: Can I set up system mail to use an external SMTP server — sleepyweasel, Feb 04 '17 at 16:36

score 0 · Answer 1 · answered Feb 04 '17 at 16:17

You can setup postfix using your GMail account as an outgoing 'smarthost' and rewrite rules to take care of outgoing mails always having the correct From: line and fetchmail+some IMAP server that supports the maildir format for incoming mails, but that's probably not what you want.

Instead, you could use the old, legacy SSL versions of IMAP and SMTP (modern clients generally establish a normal, unencrypted connection and then use STARTTLS but Google also offers the old, SSL-encrypted ones) and simply proxy your old mail client. In that case, you could use e.g. haproxy like this:

frontend smtp bind :25
mode tcp
default_backend smtp_back

backend smtp_back
mode tcp
server google smtp.gmail.com:465 ssl verify required

and put the address of the machine this is running on instead of GMail into your old mail client.

Blimey - if I can't get stunnel to work, I can't see this being any more successful! I was hoping for a solution which would be as easy as entering my account details (on the linux system), and having it (perhaps) cache my most recent emails and serve them on to the old system. Thank you for the thought though. — headbanger, Feb 04 '17 at 16:25
This is a very specific problem, so there probably is no ready-made software. If you want to download actually download and server your mails, you probably won't get around fetchmail+imap, which is difficult to set up. I was hoping that it would be just an issue with your specific stunnel configuration though. — maxf, Feb 04 '17 at 16:28

Mail Server for Linux which can forward Gmail

1 Answers1