SMTP relay - Lekalao

WordPress, an ERP, a printer that e-mails its scans: anything that speaks SMTP can go through Lekalao. Each message received leaves again as a transactional e-mail, logged, followed and counted.

The relay is a process the installation’s administrator has to run. When it runs, Settings → Documentation shows the host and the port. Otherwise, see Processes.

Connecting

Setting	Value
Host	The one shown in Settings → Documentation.
Port	The same; 2525 by default.
Encryption	Depends on the installation: none on a local network, TLS when the administrator put a terminator in front.
Authentication	`PLAIN` or `LOGIN`.
User name	Anything, `lekalao` for example.
Password	A Read and write API token.

The token is revoked like any other, in Settings → API tokens. It stops working if its owner becomes a viewer or leaves the team.

WordPress (WP Mail SMTP)

Mailer: Other SMTP
SMTP Host: smtp.lekalao.example.com
Encryption: as your installation is set up
SMTP Port: 2525
Authentication: on, Username lekalao, Password the token

Laravel or Symfony

.env

MAIL_MAILER=smtp
MAIL_HOST=smtp.lekalao.example.com
MAIL_PORT=2525
MAIL_USERNAME=lekalao
MAIL_PASSWORD=12|kJ3v8mQ2xP9…

For a Laravel application, the dedicated transport does more.

What goes through

Item
Recipients	Those of the envelope, 100 per message at most. Anyone in neither `To` nor `Cc` stays a blind copy.
Subject, sender, `Reply-To`	Read from the headers, encodings included.
Body	The HTML part; failing that, the text part, shown as it was written.
Size	25 MB at most.
Attachments	Refused: the message is rejected with `554`. Send them through the API.

What the relay answers

Code	Means
`250 Message accepted`	Taken. It is in the transactional log.
`535 Authentication failed`	Unknown or revoked token, read-only token, or an owner who may not write.
`550 …`	Sender refused. The reason follows. Change the `From` address.
`554 Attachments are not relayed…`	The message carries an attachment.
`452 Too many recipients`	More than 100 recipients.
`451 Message could not be accepted`	A passing problem on Lekalao’s side. The software should try again.