This post solves this problem:
One of my client had their website hosted on a third party dedicated server. However they were using amazon SES service for sending emails via SMTP. Everything was working fine until they decided to shift the servers to a new company. Upon shifting the server to a new data center with new company, the amazon ses emails stopped working for their system. Note that both old and new server were running cpanel and whm (web hosting manager).
Also note that the smtp was sending the emails perfectly when connected through a third party service, not through our hosting server. Which means that the issue was not with amazon side, rather it was with the server side.
How to solve the issue of amazon ses smtp failing to connect
The solutions which did NOT work for us (but worth a try) were:
- Ensure that the dns TXT record and others for amazon ses were working fine
- Checking smtp restrictions on the server, which made no difference.
What Solved the issue was a very simple thing. This is how we fixed it:
- Adding port 456 to the firewall settings, based on this tutorial: https://documentation.cpanel.net/display/CKB/How+to+Configure+Your+Firewall+for+cPanel+Services#HowtoConfigureYourFirewallforcPanelServices-Ports
I hope it helps. Please let me know if you have any query related to this.