Connect fails from php.
Connected directly from the container and it can talk to mailhog but php does not.
root@6c74662b8030:/var/www/phpList3# ./busybox telnet mailhog 25
Connected to mailhog
220 mailhog.example ESMTP MailHog
HELO
250 Hello
MAIL FROM user@example.co.uk
550 Invalid syntax in MAIL command
MAIL
550 Invalid syntax in MAIL command
MAIL FROM: user@example.co.uk
250 Sender user@example.co.uk ok
RCPT TO: user@example.co.uk
250 Recipient user@example.co.uk ok
DATA
354 End data with .
HELLO!
.
250 Ok: queued as Y4q-FqFdhZ_xfhy6VKauqxSPZdWhPROyot1VX2taTG4=@mailhog.example