lately (the last couple of days), Mail.app has been ignoring my mail server settings. It’s using Apple’s SMTP servers for my non-Apple email account. (And then Gmail says "apple servers aren’t allowed to send messages from grebyn.com.)
Anyone seen this? I’ve tried resetting the server settings in Mail.app settings for the grebyn account (the email account I’ve been using for almost 40 years…), but it appears Mail.app is IGNORING what’s in the settings.
(Behavior like this, which is often Apple ‘trying to help me out’, is infuriating! A couple days ago there was a temporary outage at Grebyn’s SMTP server. I suspect that’s when the problem started.)
Without trying to troubleshoot the details, I believe your problem could be a side effect of the recent tightening of Internet mail security.
You may find it useful to contact the person responsible for the SPF, DKIM & DMARC records on the DNS server for grebyn.com. According to “Whois grebyn.com” that should be Karl Nyberg, email: karl@grebyn.com
Why should Grebyn add Apple servers in SPF? They have their own SMTP server, which is properly configured and documented. The problem is not with Grebyn, but with Mail.app on my own machine, which has been sending mail intended for Grebyn’s SMTP server to Apple’s SMTP server.
BUT, it looks like either the latest Mac OS release, or some fiddling I did with the settings, has reset things to work correctly.
The Sender Policy Framework (SPF) record on a DNS server specifies which servers are authorized to send email from that domain.
If Grebyn has an SMTP server used to send outgoing mail from the grebyn.com domain, then that server should be listed in the SPF record for the DNS server of the grebyn.com domain. [If any other SMTP servers are to be allowed, those should be listed as well.]
FYI, SPF records also get to specify which domains (and/or subdomains) are allowed to be used in the sender’s email (Reply-to) address. If senders with anything@grebyn.com addresses should be allowed, the SPF record has to specify that. If subdomains allowed, the SPF record also has to specify that as well.]
[I’ve just been through the song-and-dance of setting up SPF (as well as DKIM and DMARC) records, and modifying outgoing SMTP server settings for the domains of several non-profit organizations with users whose outgoing mail inconsistently gets rejected or blocked, or labeled as spam.]
Correct. But my problem had nothing to do with SPF records for grebyn. Rather it’s that the Mail.app was trying to send messages with my grebyn.com return address to APPLE’s SMTP servers, a mistake by the local mail application.