Tags: howto, administrator, email

Migrate Email Sending from sendmail to SMTP#

This guide explains how to migrate server-side scripts from the old sendmail-based email setup (caosadvancedtools.serverside.helper.send_mail) to pylinkahead’s native SMTP-based send_email. After the migration, LinkAhead no longer needs access to a sendmail binary or a local mail relay on the host.

Prerequisites#

You have identified all server-side scripts that currently call helper.send_mail(...).
You have the credentials and hostname for your institution’s SMTP server, or have decided on an external relay. See Configure Email for Server-Side Scripts.

Steps#

Configure the new [Email] section in caosdb-server/scripting/home/pylinkahead.ini as described in Configure Email for Server-Side Scripts.

If your old setup used an external relayhost (configured via relayhost in custom/other/main.cf), you can point smtp_server directly at that host with no TLS or credentials – no Postfix intermediary is needed:
```
[Email]
smtp_server=relay.host.example.com
smtp_port=25
from_address=LinkAhead <linkahead@example.com>
```
Update each server-side script that calls helper.send_mail. Replace it with send_email from pylinkahead:

Old:
```
from caosadvancedtools.serverside import helper

helper.send_mail(from_addr="linkahead@example.com", to=recipient,
                 subject=subject, body=message, cc=cc, bcc=bcc)
```
New:
```
from linkahead.utils.email import send_email

send_email(message=message, to=recipient, from_address="linkahead@example.com",
           subject=subject, cc=cc, bcc=bcc)
```
The key differences:
- body is renamed to message and becomes the first positional argument.
- from_addr is renamed to from_address. If you set from_address in the [Email] section of pylinkahead.ini, you can omit it from each call entirely.
- subject, cc, and bcc remain unchanged but are now keyword arguments.
- send_mail_bin has no equivalent and should be dropped.
Developers can use the test email setup to verify their changes locally before deploying.
Remove the old configuration:
- In caosdb-server/scripting/home/pylinkahead.ini, remove the sendmail entry from the [Misc] section:
```
[Misc]
sendmail=/usr/sbin/sendmail  # remove this line
```
- If you had a relayhost setup and custom/other/main.cf is not used for anything else, delete it.
In your profile.yml, set mail to false and remove the sendmail entry (or leave it – it is ignored when mail is false):
```
mail: false
# sendmail: /usr/sbin/sendmail  # no longer needed
```
If the local mail relay (e.g. Postfix) was running solely to support this setup and is not used for anything else, you can now decommission it.