Can't receive email from a specific website. Error 450 4.1.7

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1
SYSTEM INFORMATION
OS type and version: Ubuntu 18.04 LTS
Webmin version: 1.981
Virtualmin version: 6.16
Related products version: Postfix 3.3.0

I’m trying to receive a password reset email from a website razorpay.com. Say my account is xyz@domain.com. I’m getting the following logged into mail.log when requesting a password reset mail.

Sep 18 20:56:33 primary postgrey[1471]: action=pass, reason=triplet found, client_name=mail213.static.mailgun.info, client_address=104.130.122.213/32, sender=bounce+84c1d0.674e4-xyz=domain.com@razorpay.com, recipient=xyz@domain.com
Sep 18 20:56:33 primary postfix/smtpd[15358]: NOQUEUE: reject: RCPT from mail213.static.mailgun.info[104.130.122.213]: 450 4.1.7 <bounce+84c1d0.674e4-xyz=domain.com@razorpay.com>: Sender address rejected: unverified address: host aspmx.l.google.com[142.251.10.26] said: 550-5.1.1 The email account that you tried to reach does not exist. Please try 550-5.1.1 double-checking the recipient's email address for typos or 550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1  ht; from=<bounce+84c1d0.674e4-xyz=domain.com@razorpay.com> to=<xyz@domain.com> proto=ESMTP helo=<mail213.static.mailgun.info>

Not sure why this is happening. I am getting mails from other places. Even one from razorpay.com (not the password reset). Why is this mail not getting delivered. Please help.

2

Has this Virtualmin been configured to use the Mailgun API to verify email addresses before sending / accepting mail? Note that such a check could be part of a third party anti-spam software that has been installed.

See https://help.mailgun.com/hc/en-us/articles/360011804533-Sender-Verification-Error

3

I don’t have mailgun installed. I wonder if postfix is sending an email back or somewhere else and its getting a bounce from there? I’m not sure what postfix is doing here.

Only these 2 lines are added to the logs when requesting the reset email. Could there be any other log file with more information?

4

Looks like maybe the email address got added to a greylist file.

look in the /etc/postfix directory to see if you see anything

You can add the email address to a whitelist. I’m not sure of the format of adding email addresses.
/etc/postfix/postgrey_whitelist_clients.local

5

Its not getting whitelisted. I don’t get these mails at all. Greylisted mails do arrive after some time.

6

Are you sure? This is part of your error message: helo=<mail213.static.mailgun.info>

7

Its not a free software. Pretty sure I didn’t pay them hahaha