Applies to: All Reolink Cameras & NVRs.
The SMTP Server and Port may vary depending on the mailbox that you are using. If you set Gmail as the Sender Address, you may leave the default SMTP Server (smtp.gmail.com) and default Port (465 when SSL or TLS is enabled and 25 when SSL or TLS is disabled) unchanged. However, if you set other mailbox, such as Hotmail, Yahoo mail, as Sender Address, you will need to input the corresponding SMTP server & SMTP port for the e-mail test.
Here for your reference: