Gmail is unreliable

Today we were working with a partner company on a common project. I was sitting behind a colleague's back when he wrote a message to me with several notes and sent it. He used an email at Gmail and sent it to my mail which was also at Gmail.

When I got in my office his mail was not in my inbox. I just asked him to verify he did hit the Send button and he confirmed that the message was in his Sent folder.

At this point I suspect the Gmail IMAP service which I was using with Kmail. Logging in via the web interface gave me no different results.

My colleague confirmed my address was correct by sending it to me. I even wrote this one liner to verify the address was spelled correctly with e.g. no Cyrillic symbols in it:

perl -we 'my $a="deliank\@gmail.com"; my @a=split("", $a); print($_ . " - " . ord($_), "\n") foreach @a;'
d - 100
e - 101
l - 108
i - 105
a - 97
n - 110
k - 107
@ - 64
g - 103
m - 109
a - 97
i - 105
l - 108
. - 46
c - 99
o - 111
m - 109

A minute later he decided to forward the message once again. No success this time too. He also suggested to try searching for the message in my Spam folder at which I replied s.t. like:

You must be kidding me. From Gmail to Gmail in Spam ?! You've made a big amateurs out of Google ...

I was quite amused when only the second message arrived several hours later and it was indeed in the Spam folder !

Up-to this point I had confidence in Google's services. From now on, I don't.