> Any questions were allayed with "oh, you know email. Strange things happens, delays and all that".

The funny thing is, on the real internet with SMTP (so, not in your case but commonly), that's actually true; I once worked at a company that sent a massive amount of email to customers with our own postfix clusters, and it turns out things like "MX was down for a few hours" or "customer's email system rate limited us" - or rarely even "our servers are overloaded and trickling mail out" - are real things and sometimes emails do get held up for hours or days.