I resolved it - what i did, was my
AWS SES IAM (smpt) code was written in
Terraform. The issue was, it was the wrong credentials because terraform had another set of credentials but i manually deleted the
Access Key in AWS and manually added it and kept testing with wrong credentials.
Solved it by removing the Access Key manually from the IAM user i created for mattermost, re-ran
Terraform Plan and Apply (gave me a new Access Key and Secret). Then ran
terraform output to get the new access key and secret - used those creds and placed it in the
mattermost config, kept port 587 by the way and changed it from
STARTTLS - and tested the connection and all came through and worked ( emails were sent).