I can't receive certain emails from Amazon

CentOS Linux 7.9.2009 (Core)
Plesk Obsidian Version 18.0.40 Update #1, last updated on Jan 6, 2022 08:04 AM
QMail psa-qmail 1.03-2.centos.7+p18.0.41.0+t211130.1601

I host websites. I also host my own web site. I am having an issue with my own account.

I go to Amazon. I try to change my email to one that I host.

Amazon says: We've sent a One Time Password (OTP) to your email address. Please enter it below.

But I never receive it.

I go to Tools & Settings > Server-wide mail...

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