Explanations for people not receiving emails

On two occasions recently people did not receive important emails I had sent them.

On one occasion, I was able to send it to a different email account they had access to, and they did receive it.I am trying to identify the possible reasons.

Problem at my side
1) Wrong email address.
So I got them to email me and I replied, so I have the right email address.
2) Something else wrong at my side - so I cc'd it to another email address who got the email. I get many responses to my emails, so it is working generally.

Problem at their side
3) The attachment was causing a problem - I sent them an email without the attachment and they did not get that either
4) quarantine - they checked their quarantine and it wasn't there.

They do not seem to have problems receiving emails from other people.

One is a gmail account, the other is a bmx account.

could be spamfilters on the ISP end or their personal firewall perhaps?

The gmailer may be filtering your message by either content (word/subject line) and deleting the email instantly (without making it to spam)

Get them to check their trash!

If they're anything like my mother then check their mail filter rules. There may be a rule in place which is filtering your mail off to a folder so it looks like it hasn't been received when it has, but it's just not in the inbox.

For example, maybe your friend got a lot of mails advertising "male enhancement products" so they created a rule which moved mails matching the subject line to another folder. Then you sent them a mail with a subject line like "Great enhancement idea for your business". If the rule was sufficiently vague (like subject contains "enhancement") then it might match your mail and stick it off in the folder. Or delete it. Depends on the action they assigned.

The best way to check for the presence of a mail (in my books) is to send a test mail with a unique/quirky word in the subject line - say "bigelephant".

Then do a search in the recipients *entire* email for that word. Unless they have some strange friends there should only be one mail with that subject line. If you find it then you just need to work out why it ended up wherever it ended up.

Alternatively, create a mail rule that plays a noise when a mail is received from you. Put it at the top of the list of mail rules. Then send a mail and wait for the noise. If they hear the noise then the mail arrived (and they need to work out what happens after this). If they don't hear the noise then the problem is further back and you can move the focus back there.

z

I often email presentations. With some, attaching the powerpoint (or other) will work and be received. However, with some others their systems are protected and therefore cannot open the file. In order to get around this, you need to compress the folder before sending it. It may also be to do with the limit of memory on their accounts.

If they are using gmail through Outlook, there would be two levels of spam filtering. First, gmail itself may filter some spam. Log in to gmail via the web interface to check what is in the spam folder. Then outlook may push things into the Junk Mail folder, which can be checked by opening it up.

I had a similar problem where the recipients email server (imagine) stopped the message because it was over 17.5 mbs - I didn't get a message back to say they couldn't receive it and they didn't get the email but about two weeks later (possibly more) I got an email saying message couldn't be delivered.

I had a problem last year on a work email. Some people didn't receive emails I sent and I didn't receive some emails sent to me, the puzzling thing was that I was able to send and receive some emails, there was no logic or pattern. The I.T. company said that what I was saying didn't make sense however when they linked into my email account and we got various people to send emails to me they said that the emails were "going into a black hole" and they couldn't trace them! To cut a long story short the problem lay with the broadband provider, which in this case was eircom, who eventually got it sorted.

There is a far superior email protocol called X.400 out there (http://en.wikipedia.org/wiki/X.400), but it never really took off. Some MS Exchange users may be able to use X.400 addressing, if the right interconnections are in place. This does offer guaranteed confirmation of delivery (or otherwise).

It could also be good old-fashioned 'blame the computer' for human error. Use of return receipts can help, but are never guaranteed on Internet emaill