SMTP on Zerops

Keywords

smtp, email, mail, sendgrid, mailgun, ses, gmail, port 587, starttls, send email

TL;DR

Only port 587 (STARTTLS) is allowed for outbound email — ports 25 and 465 are permanently blocked. Use an external email service.

Port Configuration

Port	Status	Protocol
25	Blocked	Traditional SMTP (spam risk)
465	Blocked	Legacy SMTPS (deprecated)
587	Allowed	SMTP submission with STARTTLS

Provider Configurations

Provider	Host	Port	Username	Password
Gmail	smtp.gmail.com	587	user@gmail.com	App password
Google Workspace	smtp-relay.gmail.com	587	user@domain.com	Regular/App pass
Office 365	smtp.office365.com	587	user@domain.com	Account password
SendGrid	smtp.sendgrid.net	587	apikey	API key
Mailgun	smtp.mailgun.org	587	postmaster@domain	Password
Amazon SES	email-smtp.{region}.amazonaws.com	587	Access key	Secret key

Configuration Example

envVariables:
  SMTP_HOST: smtp.sendgrid.net
  SMTP_PORT: "587"
  SMTP_USER: apikey
envSecrets:
  SMTP_PASSWORD: <sendgrid-api-key>

Gotchas

1. Port 25 is permanently blocked: Cannot be unblocked — use 587 with STARTTLS
2. Port 465 is also blocked: Legacy SMTPS is deprecated — use 587
3. Gmail needs App Password: Regular Gmail passwords won't work — generate an App Password in Google Account settings

See Also

• zerops://guides/firewall
• zerops://guides/environment-variables