Hi @cgsmith, this would happen if your SMTP server uses STARTTLS instead of SSL. An indicator for this is often a port other than 465, and SSL/TLS toggle would need to be off for STARTTLS.
SSL should still work though, I’ve just tested the below config and the email went out as expected:
Ok - I changed to 465 and it gave the error below. I am using PostmarkApp if it matters.
Error: Connection timeout
at SMTPConnection._formatError (/root/.nvm/versions/node/v18.12.1/lib/node_modules/n8n/node_modules/nodemailer/lib/smtp-connection/index.js:790:19)
at SMTPConnection._onError (/root/.nvm/versions/node/v18.12.1/lib/node_modules/n8n/node_modules/nodemailer/lib/smtp-connection/index.js:776:20)
at Timeout.<anonymous> (/root/.nvm/versions/node/v18.12.1/lib/node_modules/n8n/node_modules/nodemailer/lib/smtp-connection/index.js:235:22)
at listOnTimeout (node:internal/timers:564:17)
at processTimers (node:internal/timers:507:7)
I then kept at 465 but removed SSL/TLS option and received the same timeout.
From checking their documentation at SMTP Service | Postmark you might have to use port 587 and the SSL/TLS switch set to “Off” (so n8n uses STARTTLS instead of SSL).