sendmail alternative / smtp relay
A Sendmail alternative that takes mail delivery off your server.
A mail server of your own means queues, patches and a sending reputation to look after. Yantra Mailer is an SMTP relay: your server hands over each message, and delivery, retries and bounces happen here.
● inside yantra
What you get.
Use it as a Sendmail smart host
Keep Sendmail and point it at smtp.mailer.yantra.app on port 587. The sendmail command, cron mail and PHP mail() carry on, and everything leaves through the relay.
Or retire the mail server
Anything that speaks SMTP can connect to the relay directly, so there is no local queue to watch and no mail server to patch.
Encrypted, on the port your host allows
Connect on 587 or 2525 with STARTTLS, or on 465 with TLS from the first byte. Logins are only taken once the connection is encrypted.
DKIM for your own domain
Add your domain, publish the DNS records it gives you and mail goes out signed with its own DKIM key. The live check tells you when each record is right.
A log of every message
See each message go from accepted to delivered or failed, with the reason, instead of reading mail logs over SSH.
Bounces handled for you
Deliveries that fail are retried, and addresses that bounce, complain or unsubscribe are suppressed per domain, in a list you can search and edit.
● side by side
Yantra or Sendmail?
| what you need | Yantra Mailer | Sendmail |
|---|---|---|
| Where it runs | Hosted by Yantra | On a server you run |
| Queues, retries and bounces | Handled for you | Handled by your server, which you set up and watch |
| DKIM signing | Built in, with a key for each domain | Added with a mail filter such as OpenDKIM |
| Seeing what happened to a message | Searchable logs in the control panel | The mail log on your server |
| Where your mail goes | Through Yantra on its way out | Only through machines you choose |
| Source code | A hosted service | Open source |
Choose Yantra Mailer if you want mail off your servers and delivery to stop being a job you look after.
Choose Sendmail if you need an open source mail server that you run yourself, with your mail staying on machines you control.
Sendmail details come from its public website and documentation as of November 2026 and can change. Sendmail is a trademark of its owner. Yantra is not affiliated with or endorsed by Sendmail. Source: www.sendmail.org.
● try asking
Start with one prompt.
Pick one and it lands in the composer, ready to send.
● questions
Asked often.
What is the best Sendmail alternative?
For most servers, not running a mail server at all. Yantra Mailer takes delivery, DKIM, retries and bounces off your machine and works with anything that speaks SMTP.
Sendmail vs Yantra Mailer: which should I choose?
Choose Sendmail if you need an open source mail server of your own and want your mail to stay on machines you control. Choose Yantra Mailer if you would rather hand delivery off and see every message in one place.
What is an SMTP relay service?
A hosted server that takes your outgoing mail over SMTP and delivers it for you. Your app or mail server logs in, hands over the message and the service does the rest.
How do I set up a Sendmail smart host?
Create SMTP credentials for your domain. In sendmail.mc, set SMART_HOST to smtp.mailer.yantra.app and RELAY_MAILER_ARGS to TCP $h 587, add FEATURE(authinfo) with your login and rebuild sendmail.cf. Sendmail needs STARTTLS and SASL, which the Debian package has.
Which addresses can my server send from?
Addresses on a domain you have verified, so root@ your hostname is refused. In Sendmail, MASQUERADE_AS with FEATURE(masquerade_envelope) puts your domain on outgoing mail.
Which ports does the SMTP relay use?
587 and 2525 with STARTTLS, and 465 with TLS from the first byte. A message can be up to 25 MB and go to up to 1,000 recipients.
Is Yantra Mailer part of Sendmail?
No. Yantra Mailer is our own email service. It takes mail from Sendmail the way it takes mail from any other SMTP client.
● also in yantra
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