Containers running on the Toolforge Kubernetes cluster do not install and configure a local mailer service like the exim service that is installed on grid engine nodes. Tools running in Kubernetes should instead send email using an external SMTP server. The mail.tools.wmflabs.org service name should be usable for this. This service name is used as the public MX (mail exchange) host for inbound SMTP messages to the tools.wmflabs.org domain and should always point to a server that can process both inbound and outbound email for Toolforge.
Original bug report:
Currently, it seems that it's not possible to send email from PHP (with either the php5.6 or php7.2 container). We only want to be able to send to the tool maintainers' email address (for T204860).
Following the instructions for mailing from tools gets the error "/usr/sbin/exim: No such file or directory".
This might already be possible, in which case I'd love someone to tell me how to do it. Thanks!
(This is a follow-up from T188318#4628389.)