Forum Discussion
Mohan Seenippandian
Apr 19, 2017Brass Contributor
DKIM for O365 Relay (On-premise SMTP server)
Good afternoon - I have enabled DKIM on one of the domains in O365/EXO and published required Cname records in DNS. I have a relay connector setup through Office 365 that our on-premise SMTP Serv...
myFirstAccount
Oct 01, 2018Copper Contributor
Replying to old topic...
Walked into this also, but my guess is that this is normal behaviour. You allready validated the recipient by creating a reveive connector for. Thus DKIM not applied.
Try relaying to a mail partner (external recipient). My guess is that DKIM applies to that one !
- Winnie_SouthMay 05, 2021Copper Contributor
myFirstAccount
You're right.
On-Prem Exchange SMTP relay to O365 DKIM=noneOn-Prem Exchange SMTP relay to External such as gmail DKIM=pass
My issue, is ExchangeOnlineProtection is marking On-Prem to O365 as SPAM (5). I figured that by adding DKIM the spam rating would likely reduce.
Not wanting to whitelist the on-prem exchange server for the SPAM filter, I'll look at switching from anonymous relay to authenticated to try and lower the spam confidence level...- Steffen_JosefsenMay 28, 2021Copper Contributordid you ever find a workaround to O365 DKIM=none?