Add the MX and SPF records on ses.your-domain.com so bounce handling and SPF alignment work.
You got custom MAIL FROM MX/SPF is incomplete. Lumail sends with a custom MAIL FROM of ses.your-domain.com. That hostname needs its own MX and SPF. Without them, bounce handling and SPF alignment break.
Copy the MAIL FROM rows from Domains → the domain. They look like this:
| Type | Host | Value |
|---|---|---|
| MX | ses.your-domain.com | feedback-smtp.REGION.amazonses.com (priority 10) |
| TXT | ses.your-domain.com | v=spf1 include:amazonses.com ~all |
The MX target is region-specific. Use the value on the domain page, not a guess.
ses relative to the sending domain (so ses.hey.melvynx.com if you send from hey.melvynx.com).10.ses hostname, not only on the apex.ses.your-domain.com that steals the name.Then verify on the domain page.