Forum Discussion

Copper Contributor

Sep 23, 2019

Solved

External client SMTP Relay with group alias in From address field -- fails to send

Here is the situation: 1. Using an inventory system that handles our packing and shipping lists a. System emails copies of shipment records to clients using SMTP relay i. Syst...

Microsoft 365 Groups

office 365

NunoAriasSilva
Sep 23, 2019
Hi TheCoreSquirrel,

Based on your scenario the best option is to implement "Option 3" on the following article https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-office-3

For best security, please implement on your firewall that only your inventory system can contact Office 365 in port 25 or required servers.

Best regards,

Nuno Árias Silva

NunoAriasSilva

MVP

Sep 23, 2019

Hi TheCoreSquirrel,

Based on your scenario the best option is to implement "Option 3" on the following article https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-office-3

For best security, please implement on your firewall that only your inventory system can contact Office 365 in port 25 or required servers.

Best regards,

Nuno Árias Silva

Forrest_H
Iron Contributor
Sep 25, 2019
I have also had success applying a password to the account associated with the O365, security group, and shared mailboxes in these types of scenarios. This allows the account to authenticate to do the SMTP .
TheCoreSquirrel
Copper Contributor
Sep 25, 2019
NunoAriasSilva

Thanks very much, I will pass this along to our IT Admin and reply with the results; this sounds right to me though, so I hope it'll work.