SMTP setup (AWS SES) - 535 error

Hi everyone,

Setting up community Mattermost on a fresh install of Centos 7:

Mattermost Version: 5.37.1
Database Schema Version: 5.37.1
Database: mysql

Trying to add the SMTP server, I’m using AWS SES. Credentials are known to be working on v5.35.1

Repeatedly getting the following error:

{“level”:“error”,“ts”:1629060028.369844,“caller”:“mlog/log.go:251”,“msg”:“Connection unsuccessful: authentication failed: 535 Authentication Credentials Invalid”,“path”:"/api/v4/email/test",“request_id”:“ifnjcb8m3pb6j86p7prmkxfpke”,“ip_addr”:“”,“user_id”:“fnx9q5uubin1ddarwmtrsuy7dy”,“method”:“POST”,“err_where”:“testEmail”,“http_code”:500,“err_details”:""}

any thoughts? thanks in advance!