Email address is constantly blocked

[DiVojich]

Hi all,

looking for advice regarding blocked email addresses.

In protection.office.com/restrictedusers I have 1 email address that is being blocked every 48h.

The issue is, this is really important to address & it is not sending SPAM/PHISH of any kind.

The address is being used to send a lot of emails (to users in 15 different countries).

It sends around 1000 emails every 24-48h & it is automatically blocked by Microsoft.

Any idea of how to stop this blocking?

Kind regards

[#2]

Hello! @DiVojich 

How is the mail address sending these bulk emails? Is it over port 25 ( Un authenticated SMTP ) 
Or bort 587 ( Secure SMTP ) 

We need this information to assist further. 
Basic Anonymous mail over port 25 usually gets blocked in these bulk scenarios.

Kind Regards
Oliwer Sjöberg

[#3]

Hi, it is port 587@oliwer_sundgren