Welcome Email Not Sending To One User

[kite]

I have an Azure hosted 3CX PBX, that's using 3CX SMTP Server to send Welcome Emails. It's working with the exception of one user. I've confirmed that the emails are not going into spam. The recipient mail server is not receiving an email.

How can I troubleshoot this? Do I need to open a ticket with 3CX and pay for support?

 

[QueBall]

You likely spelled the email address incorrectly.
Delete the email field, save it, type it in again and resend.

Or just change email address, send it to yourself and forward the email and then change the email address back again if it really doesn't work. Perhaps the username triggers some kind of filter. Maybe add another email alias to the user on your end and try sending to that name instead.

 

[kite]

You likely spelled the email address incorrectly.
Delete the email field, save it, type it in again and resend.

Or just change email address, send it to yourself and forward the email and then change the email address back again if it really doesn't work. Perhaps the username triggers some kind of filter. Maybe add another email alias to the user on your end and try sending to that name instead.

It's Microsoft 365 integrated, so the email address is definitely correct. As a workaround, I did change the email address to a working user, sent the Welcome email, and then changed it back. Her mailbox is receiving emails, otherwise. Just not from this PBX.
Switching to Microsoft 365 as an SMTP source, the email goes through fine. So it definitely must be something w/ the 3CX SMTP Server.
Digging through some old posts, I found one that advises that 3CX SMTP has a bounce protection. If it receives a bounce back from an email address, it will not resend emails for another week. So I think that's my issue here. Just no way to confirm it.

 

[Agathocles Prodromou]

Hi,

Please send me a PM with the email address in question.