XMPP Service Operators - 2025-06-13


  1. tom

    Can we use macs ciphers besides RSA1024 now for DKIM signatures?

  2. tom

    A few years back I tried using longer DKIM RSA keys but ran into issues with incorrectly configured legacy hosts who could not fall back to DNS/TCP or handle IP fragments properly which is needed to handle such long DNS responses. I tried signing both with RSA and a modern elliptic curve based cipher but a lot of legacy mail hosts got confused by this and could not correctly use a dkim selector they implemented if mails had multiple signatures on them.

  3. tom

    I'm revisiting DKIM now after an AXFR transfer between two providers mangled some long txt records and would not to stop using weak legacy ciphers with weak key sizes