Weirdest Email issue ever

[digibucc]

Hello TPUninites

first a little background:
I have got tech support working on this, and am following a few lines of investigation but just wanted to put this out there, and see what other people thought.
For my job I run 5 websites for a single company. They are service websites offering Social networking, job searching within a specific career track, etc. nothing too heavy or crazy.
to run these sites we have a dedicated server. It is managed by the hosting company but I can also create accounts, add ips, domains, etc. They do the work but I have control as well.
PHP/Mysql, Nix

NOW, to the actual issue at hand:
seemingly totally at random, sent emails simply disappear. It seems to happen with Outlook, but we use Outlook 95% of the time so it could just be that.

But the email goes through the sent process. if there are multiple recipients some have gotten it others haven't. No spam message returned. and by taking their words it is not in their spam or junk mail.

it happens with yahoo, hotmail, corporate hosts, other dedicated server hosts (shared server hosts as well) The recipient can be using outlook or not.

Now my first inclination is to not believe the recipient. My first and strongest inclination. however it seems to be happening more often than it ever has before. some random losses can be written off as human error, but it's happening 1-5 times a week

so, any thoughts? what else could it be? every test I have done to my own yahoo, hotmail, etc, all go through no problem... i see no other solution than it's the recipient... however my bosses don't like that answer.... any ideas?

thanks all,
Kyle

[Easy Rhino]

what is your MTA ?

[Msap14]

try to reinstall email clients you are using (outlook)

does your server posibly have filter of some sort running?
are ports blocked on firewalls?

[Cybrnook]

How many hops are the mails making prior to going "out" of your email chain?

For example, here in my office, any outside mail is making 3 hops prior to leaving our mail flow. So, If someone says they sent a mail but thinks the recipient did not get it, I can trace it up to the point of leaving. (check message headers/hops)

[digibucc]

good q's - was gone for the weekend so i will get some answers today.

msap - have reinstalled, have checked filters/forwards/everything . all clear. only regular windows firewall enabled - and most emails send fine it's just a few every few days fail.

@cybrnook - out of our office it's only one hop, idk off the top of my head how many to the host. I have had our host check all logs, and they have confirmed some individual problem emails DID leave our mail server. so they left no problem and then disappeared.

as for the MTA rhino, i don't know... I have seen that before but don't know where to look for it.

[Cybrnook]

Is it any particular "one client/recipient" that is having problems receiving your mail? If your host confirms that the mail reached them and left, and you can trace the hops all the way back to leaving your office, then I would say its a recipient problem. Perhaps your mails are being flagged as spam and caught for some reason. (Maybe a header, embedded url's etc.....)

[digibucc]

just wanted to update everyone.

it seems 99% of the problem emails were to yahoo. we had gotten some complaints after our last LEGITIMATE mass mailing. We have an opt-in/opt-out program , and the mails are about job offers and services, not selling things. We have only EVER done 3 mailings, but one of them caused some issue, and yahoo put some kind of invisible hold on it. Our emails just disappear with no message.

So I am in the process of battling it out with Yahoo. in the meantime we have begun sending our daily business mailings to yahoo from a yahoo address, and have had no reports of missing mail. the other few percent of random addresses I am guess was user error.

so yeah, Yahoo sucks. whoever complained sucks because they said yes to the mailer when they didn't have to, and the mailers are not junk spam. they are again job offers (my company/website helps place people in jobs, basically a referral service but done differently)

[Easy Rhino]

Originally Posted by digibucc

just wanted to update everyone.

it seems 99% of the problem emails were to yahoo. we had gotten some complaints after our last LEGITIMATE mass mailing. We have an opt-in/opt-out program , and the mails are about job offers and services, not selling things. We have only EVER done 3 mailings, but one of them caused some issue, and yahoo put some kind of invisible hold on it. Our emails just disappear with no message.

So I am in the process of battling it out with Yahoo. in the meantime we have begun sending our daily business mailings to yahoo from a yahoo address, and have had no reports of missing mail. the other few percent of random addresses I am guess was user error.

so yeah, Yahoo sucks. whoever complained sucks because they said yes to the mailer when they didn't have to, and the mailers are not junk spam. they are again job offers (my company/website helps place people in jobs, basically a referral service but done differently)

yahoo is a giant pain in the ass. you have to bend over backwards to get on their white list. sure, if you have an account their spam protection is very good, but if you are sending them email you must contact them.