Starting March 7th our SMTP outbound servers will only support encrypted connections using TLS

We will disable support for SSL v3 on March 7th, and going forward our servers will only support encrypted SMTP connections using TLS (1.0 - 1.3). Most customers will not be affected by this change. However, you can double check that your SMTP client is compatible by temporarily sending mail through future-smtp.postmarkapp.com instead of smtp.postmarkapp.com.

future-smtp.postmarkapp.com points to the new servers (and new IPs) and it does not allow SSL v3 connections. If you use connection to test and everything works well, no further action is needed and sending should continue through our current endpoint: smtp.postmarkapp.com.

If you are having trouble connecting over future-smtp.postmarkapp.com you will need to update your SMTP client. Please can let us know if you are not able to resolve or update your SMTP client before the switchover date.

Sign up to receive new updates by email