Forum Discussion
Tim Hunter
Jan 23, 2019Steel Contributor
Mail without TLS
I am getting some messages in my Office 365 about Mail without TLS. Is there any concerns here? Do I need to make any changes?
Tim Hunter
Jan 23, 2019Steel Contributor
Is TLS something I can turn on in Office 365 or does that have to be done with my Domain Registrar?
Jan 23, 2019
You already have it on. Hence the sent and received TLS 1.2 messages. It’s an endpoint you deal with that they have it off on their side. You’ll have to investigate to see if it’s mostly the same one and get them to turn it on or just ignore it / increase that alert threshold.
- Tim HunterJan 23, 2019Steel Contributor
Here is the Connector I am using that is getting the TLS warnings.
- VasilMichevJan 24, 2019MVP
Switch to using the other option, "By verifying that the subject name on the certificate that the sending server uses to authenticate with Office 365 matches this domain name". Details for example here: https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/use-connectors-to-configure-mail-flow/set-up-connectors-to-route-mail#part-2-configure-mail-to-flow-from-your-email-server-to-office-365
You can also toggle the RequireTls parameter.