How do I fix SMTP authentication failures?

Steps

1. Check that the SMTP Host, SMTP Port and Encryption match your provider's instructions. SSL goes with the implicit-TLS port (usually 465), TLS with the STARTTLS port (usually 587).
2. Check the SMTP Username. Most providers expect the full email address.
3. Confirm the password at your provider: if you use 2-step verification, your provider may require an app password, and SMTP access may need to be turned on.
4. In Email Accounts, open the account's menu (⋮), choose Edit, correct the details and click Update Account. Leave a password field empty to keep the saved password.
5. Run Test authentication from the same menu to confirm.

Good to know

• After you change the password at your provider, update it in MailRush; sending and reply detection stop until you do.
• If an account's login fails, its warmup pauses for a few hours.
• MailRush email accounts cannot be edited from this form. If their test fails, open a support ticket.