the notification-manager send email failed

the notification-manager version is v1.4.0

the error log


level=info ts=2023-08-21T07:31:32.217747701+08:00 caller=config.go:601 msg="resource change" op=add name=default-email-config
level=info ts=2023-08-21T07:31:32.217852149+08:00 caller=config.go:601 msg="resource change" op=add name=default-wechat-config
level=info ts=2023-08-21T08:13:13.761899063+08:00 caller=config.go:601 msg="resource change" op=add name=global-email-receiver
level=info ts=2023-08-21T08:13:13.762065138+08:00 caller=config.go:601 msg="resource change" op=add name=global-wechat-receiver
level=error ts=2023-08-21T08:42:37.058250596+08:00 caller=email.go:193 msg="EmailNotifier: notify error" from=xxxx@xxxxx.com to=xxxxx@qq.com error="find auth mechanism: unknown auth mechanism: NTLM"
level=error ts=2023-08-21T08:42:37.058833098+08:00 caller=email.go:193 msg="EmailNotifier: notify error" from=sxxxxxxx@xxxxxxx.com to=xxxxxxx@xxxxxx.com error="find auth mechanism: unknown auth mechanism: NTLM"
level=error ts=2023-08-21T08:42:37.058879844+08:00 caller=handler.go:145 msg="Worker: notification sent error"

Start in email.go around line 193 and inspect how the notification manager selects email authentication mechanisms. Use the v1.4.0 error showing unknown auth mechanism NTLM to determine whether NTLM support is expected, then verify the intended behavior with an email configuration that reproduces the failure. Done should be defined as successful notification delivery or a documented unsupported configuration.

Written by the indexing model from the issue text.