LAMP with Postfix says status=sent but no mails are delivered

Hi guys!

So I setup a fresh droplet using DigitalOcean’s “LAMP on Ubuntu 16.04” preconfigured thingy. I also followed some tuts, for example this one.

Everything works just fine, except the whole e-mail stuff. I want to host a standard Wordpress site on this droplet and of course also need to send mails (contact forms and stuff). But I can’t for the life of me get the whole postfix email thing to work.

My setup: Domain: “foobar.at” (A-record set to droplet IP, MX record I left as standard from my DNS provider - do I need to change the MX record maybe??) droplet hostname: “foobar” (not “foobar.at” or “foobar-at”) Distro: Ubuntu 16.04 LTS Standard LAMP Stack UFW Firewall with ports 25 and 587 open

When I try to send a mail via

echo "This is the body of the email" | mail -s "This is the subject line" your_email_address

or just using a simple php script I call via the browser, the following logs appear in my /var/log/mail.log:

Dec 22 11:17:06 foobar postfix/qmgr[12785]: EC576D82A: from=<www-data@foobar.at>, size=383, nrcpt=1 (queue active)
Dec 22 11:17:07 foobar postfix/smtp[12791]: EC576D82A: to=<myaddress@gmail.com>, relay=gmail-smtp-in.l.google.com[173.194.69.26]:25, delay=0.52, delays=0.01/0.01/0.34/0.17, dsn=2.0.0, status=sent (250 2.0.0 OK 1482405427 em6si31461231wjb.114 - gsmtp)
Dec 22 11:17:07 foobar postfix/qmgr[12785]: EC576D82A: removed

So if I understand this correctly it says status=sent (250 2.0.0 OK) which sounds good to me. But I do not receive any emails … not even in the spam folder of gmail!

What am I doing wrong? What am I missing here? Maybe something with my domain records is wrong?

Thanks a bunch in advance, best P