The mailing list for listmasters using Sympa

["John Levine" <address@concealed>]

In article 
<address@concealed>,
Steve Fisher <address@concealed> wrote:
>Now I see in
>https://sympa-community.github.io/manual/customize/dkim-arc.html that I
>should get  Mail::DKIM <https://metacpan.org/release/Mail-DKIM> and
>configure that as well. My outgoing messages are being signed by postfix
>already. What is the added benefit of doing it in Sympa and do I need to
>stop postfix doing it as well?

If you just want DKIM signatures, either is OK. If you also want ARC
seals, which at some point will make it more likely that large mail
systems will accept our list mail without ugly anti-DMARC hacks, I
don't think that Postfix can do that so you should use the code in
Sympa which adds both.

Signing in both Sympa and Postfix won't hurt anything since you're allowed
to have all the DKIM signatures you want on a message.