The test has two issues:
- it uses /var/spool/mail instead of /var/mail
- the client often takes more than 30 seconds to connect to the smtpd server,
because the server tries to perform name resolution on 10.0.2.3
* gnu/tests/mail.scm (%qemu-static-networking-no-nameserver): New variable.
(%opensmtpd-os): Use it instead of the dhcpcd-service-type service.
(run-opensmtpd-test): Use /var/mail instead of /var/spool/mail.
Fixes: guix/guix#3978
Change-Id: I429edbf2460f380f8a617ee1fccd145f34a1f3d6
6aded64869