Can Office365 shared mailbox use SMTP?

Question

Need to set up service account on company printer, that sends print counters to copy company. So they can send us back the invoice.

I was told, that this could be handled by shared mailbox without any licence. But it seems to me, that shared mailbox crendentials can not auth with SMTP.

Do I need to buy licence? If so, which one?

Answer 1

Office 365 Shared Mailboxes (user without Exhcange licence) do not have SMTP access to Exchange online, which is a bit different from behaviour you might expect when coming from on premise Exchange. They can connect using the Exchange protocol in outlook thou, but that is no good for various devices.

There are several options described in Office 365 documentations on how to connect various devices: https://docs.microsoft.com/cs-cz/Exchange/mail-flow-best-practices/how-to-set-up-a-multifunction-device-or-application-to-send-email-using-microsoft-365-or-office-365

To put it simply:

1. For devices that need to send only to internal mailboxes (for example printers and server alerts) I went with Option 2, which does not require licensing. You just setup spf records and allow your public ip address in Office365.

You can send to distribution list, which forwards to specific mailboxes outside your organization.

2. If you need to send mail outside your organization (for example invoice notifications), you need licensed user, probably cheapest one is Exchange online plan 1.

One licensed user can operate multiple assigned shared mailboxes, if you don't mind exposing same credentials on different places.