Stuff I'm Up To

Technical Ramblings

Exim4, DKIM & Smarthost — October 13, 2016

Exim4, DKIM & Smarthost

Following on from the previous post Exim4 & DKIM I ran into a problem with no DKIM signature being added to outgoing mail. As I had this working when sending emails directly I figure it has to do with the smarthost config in Exim4.

Turns out the problem is that there is no DKIM config in the smarthosts config section.

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Exim4 & DKIM — October 8, 2016

Exim4 & DKIM

Where possible I try to get mail systems setup so that they can be verified as true senders by the recipient by using SPF and DKIM. Seems a shame that few mail systems actually seem to do this as it would trim a lot of spam from the net.

Having moved to another server I needed to move the mail sender with it. This particular system only needs to send email out as there is another system that receives mail for this domain. So All I need do is install an SMTP service and make sure it signs it’s messages with the same private key as I previously used, so it matches the public key that is published in DNS.

Previously the system used Postfix and OpenDKIM, but as this needs to be a barebones simple system I figured I’d stick with Debian’s default mailer Exim4. Turns out this was a good choice as it has DKIM built in.

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