esackbauer its really strange, i tested sogo , windows email clients, pop and imap, with and without attachment on primary domain and secondary domain with accounts on each domain, no problem at all.
Switched to iphone and mac email clients, if mailing from secondary domain on POP account, emails with attachments are blocked IF dmarc policy is set to reject. if i set it to none it passes
see log from mailgun.
"flags": {
"is-authenticated": true,
"is-routed": false,
"is-test-mode": false,
"is-system-test": false
},
"campaigns": [],
"delivery-status": {
"code": 550,
"enhanced-code": "5.7.26",
"tls": true,
"session-seconds": 1.232,
"utf8": true,
"certificate-verified": true,
"attempt-no": 1,
"description": "",
"message": "5.7.26 Unauthenticated email from xxxxxx.nu is not accepted due to domain's\n5.7.26 DMARC policy. Please contact the administrator of xxxxxx.nu domain if\n5.7.26 this was a legitimate mail. To learn about the DMARC initiative, go\n5.7.26 to\n5.7.26 https://support.google.com/mail/?p=DmarcRejection k1-20020a2e9201000000b002d0a10cfbc7si634246ljg.255 - gsmtp",
"mx-host": "aspmx.l.google.com"
},
"envelope": {
"transport": "smtp",