Mail relay account constantly getting blocked

Occasional Contributor

Hi there,


We had set up an Office 365 mail account to use for mail relay task like MFD (copier, scanner) to do "scan to email". However every now and then the account will be blocked in Office 365 for sending out SPAM. We then had to go to Office 365\Exchange Admin Center\Protection\Action Center to unblock the account. 

I checked the mail flow and all the emails that were sent out by the account and they were all genuine/valid emails of scanned documents.

Just wondering if there is a way to whitelist the account so it doesn't get blocked for SPAM (where it isn't) please?




4 Replies

Hi ,


Its because of the limitation in O365 Exchange, please create a distribution list to resolve this issue. 

Refer this blog:


Hope this helps,


There are a few options to relay messages from internal systems/devices through Exchange Online


We have done it with an internal SMTP, which has a connector with Exchange Online, as described here or officially

Thanks Thuyavan,
Unfortunately, the account is used for MFDs (printer/copier/scanner) doing scan to email and emails are sent to random recipients which can't be grouped together.


Thanks for your reply Oleg,

I did more troubleshooting and I think my problem does relate to the fact the relay account is reaching its limit, say the number of messages being sent out in an hour. Since it was used by multiple MFDs, and at a certain situation when the account was sending a large number of messages, it failed.

I think the SMTP relay may be one option. Or just have to split the MFDs ups to use different Office 365 relay accounts.