Payroll, scanner or other software can't send email
Many programs (payroll, accounting, booking systems, scanners) send email through your Microsoft 365 account. When that stops working, you'll often see "authentication failed", "SMTP error" or "can't connect to server".
Common causes
- the password for that mailbox was changed
- MFA or Microsoft's security changes now block the older sign-in method the software uses
- a typo in the email address set up in the software
- your internet connection or IP address is blocked from sending (sometimes it works on a phone hotspot but not on the office network)
Quick checks
- Try sending a test from the software and note the exact error message.
- Check the sender email address in the software's settings for typos.
- If it's a desktop program, make sure it's up to date.
What to send us
- the name of the software and where it's installed
- the exact error message (type it out; we'll ask for a screenshot if we need one)
- the email address it sends from
- when it last worked, and anything that changed (password, new internet, updates)
We'll often need to connect remotely to fix the settings. See Remote support.