OT: Configure SPF record for lists.haxx.se

Currently lists.haxx.se does not have SPF configured. This increases 
the chance of mails from the mailing list going into spam folders. 
Previously I have seen subscription confirmation mail from lists.haxx.se 
being flagged as spam by gmail.com

Setting up the SPF record is generally considered to be good practice, 
and is quite simple by adding a TXT DNS record. The domain matching is 
based on Return-Path and does not need further configuration on 
GNU mailman side.

For other DNS-based email authentication methods, DKIM still breaks 
since mailman modify the message body to append a notice. DMARC is 
basically policy configuration from the sender to specify what to do 
with emails that fail SPF or DKIM checks. I'm not sure whether DMARC 
support is considered by spam filters of major mailbox providers.

Best regards,
-- 
Unsubscribe: https://lists.haxx.se/listinfo/curl-users
Etiquette:   https://curl.se/mail/etiquette.html