Verified domain, SES authentication refuses emails.

Hi, I found myself in a weird situation were I have a verified domain, let's say xyz.com but SES refuses emails despite the domain being verified.

• The account is out of the sandbox.
• I have successfully verified the domain.
• I have successfully sent myself an email from the SES testing, the email came as follows:

• from: mktg@xyz.com
• to: (my personal email)
• date: Mar 23, 2022, 4:44 PM
• subject: fdfdfdf
• mailed-by: custom.xyz.com
• signed-by: xyz.com
• security: Standard encryption (TLS)

However, when I send an email from my aplication on behalf of (from) mktg@xyz.com, I get this error msg: "Expected response code 250 but got code "554", with message "554 Message rejected: Email address is not verified. The following identities failed the check in region EU-CENTRAL-1: mktg , mktg@xyz.com "

Note: mktg@xyz.com is not the real mailbox and xyz.com is not the real domain.