AI suggests that the issue is likely your SMTP host setting: for Gmail, NCH’s own guidance says to use smtp.gmail.com, not gmail.com, and to enable authentication plus SSL/TLS when required. Gmail SMTP commonly uses port 587 with TLS or 465 with SSL, and Google now expects an app password for many external apps instead of a normal account password.
What to set in Express Invoice
- SMTP server:
smtp.gmail.com
- Secure connection: checked if available
- Authentication: enabled, with your Gmail address as the username
- Password: use a Google app password if your account has 2-step verification
- Port: try
587 with TLS first, or 465 with SSL if that fails
Why it failed
“Unable to connect to mail server gmail.com” usually means the server name is wrong or the connection settings do not match Gmail’s SMTP requirements. Gmail does not accept plain connection attempts to gmail.com as an SMTP server, so the app needs the actual SMTP hostname and the right encryption/port combination.
Fast fix
- Change the server to
smtp.gmail.com.
- Turn on SSL/TLS.
- Enter your full Gmail address and app password.
- If it still fails, switch the port between 587 and 465.