Allow userless email verification

[zeitderforschung]

Librechat requires EMAIL_USER and EMAIL_PASSWORD to be set to send verification emails. We have configured our SMPT relay in Google Workspace to accept emails from whitelisted IPs. But this scenario is not currently supported by LibreChat. You may want to consider this for future releases.

LibreChat/api/server/utils/index.js

Line 16 in b85c620

function checkEmailConfig() {