Resend

CAUTION

the free plan is 100 emails per day, not only 3 000 per month

WARNING

without SPF, DKIM and DMARC mail lands in spam - DMARC is marked optional, add it anyway

send from a subdomain like app.example.com - a damaged reputation stays there
copy values with the copy button - the dashboard shortens them with [...], TXT goes without quotes
DigitalOcean appends the root domain to Hostname - paste Name as is
until Verify passes, mail goes only from onboarding@resend.dev to your own address
click and open tracking off - rewritten links look like spam
the API key is the SMTP password and is shown once, from is on the verified domain
DMARC to p=quarantine after a few weeks without delivery problems

toml

host = "smtp.resend.com"
port = 465 # or 587 with STARTTLS
username = "resend"
password = "re_..."

Check: Gmail → Show original - SPF, DKIM and DMARC all PASS.

Resend ​