1. The two sites I maintain that are exhibiting it are both upgrade sites. One originally a Snitz DB brought into v1.9.3, then brought up to 1.9.5.5, and now 1.9.6.1+revisions. The other one went from 1.9.1.7 to 1.9.3 then 1.9.6.1 then 2.0 beta+revisions. Others that are clean installs after 1.9.5.5 don't exhibit this behavior (so far).

2. Same two sites are housed on different Win2008 R2 servers with SQL Server 2008 R2 as well. Both also run Plesk and MailEnable. One site communicates via 'network' to the MainEnable server - the other connects to the MS-SMTP service (alternate port but still via 'network').

Now onto the wierdness I haven't isolated yet:

One of the sites only randomly seems to send multiple notifications. The other one has more of a pattern.

Pattern on PM notifications (scenario):

Send one PM to another user, they get one notification. If they reply, I got just one. Now, If I reply back, they get 3 notifications. Reply comes back to me, and I get 4 notifications. The more we reply, the more notifications we get. In direct proportion to the number of replies.

On the Post Notifications it's a little different. You get a notification for every reply you have in a thread. So if I participate 4 times in a 30-post thread, I get 4 notifications for every post.

Your site sometimes exhibits similar behavior UNLESS I'm subscribed to a forum that the thread is in. Then I get the proper number of notifications. But if I'm just watching a topic in a forum, I get slammed depending on how many replies are in that topic (follows suit with the PM notification routine I explained above - 1 notification for every reply in a topic (regardless of how many I actually posted. But wait, there's more -- after this topic reached so many replies, it returned to sending the proper number of notifications (just one) (or was it another topic - I cannot remember now - I'll have to check my gmail).

I don't know if this helps you any or makes your tracking it worse. If there's anything else I can to to help, let me know. I don't know if there's a trigger I could attach to my sql database for you and trap the activity (say whenever a notification is added to the mail queue) or what. Just let me know --

1. Problem where email fails and gets send over and over again (which is reproducible and is a problem with the code logic)

2. problem where multiple mails get send

@squirrel

the site where you get multiple pm's is this site running the yaf 2.0 betas? did you see any related entries in the event log?

@Jaben

Maybe we should rewrite the whole code to send mails as async instead of the complicated mail table

The site that is 'fairly well behaved' as far as notifications goes -- is on 1.9.6.1 + some revisions -- The one that has much more predictable and extreme behavior ( such as 1 notification for every PM sent in a 'conversation' ) is running the new 2.0 code. The problem is with that site the notification issue got so out of hand that we had to disable notifications for PMs. I'm going to check the site logs for you and if anything in there I'll dump the data out and post here --

The thing is - many of the other sites I participate in don't exhibit the behavior (but there again, I'm also not an admin so don't see much behind the scenes for those ones). It almost seems like it's something that has to do with upgraded DBs. I am willing to bet the DB housing this site has been the product of upgrades over the years, same with my two 'trouble' sites. I really need to compare structure of DB from a fresh 2.0 install and say a 1.9.3 that was upgraded, because that's the only common ground I have with my two sites and this one here --

I'd be okay with that as long as it doesn't lose functionality.

I don't think I've received multiple emails on this forum.

On my forum, when a new user registers, SOMETIMES I get three notification emails. I'd say it happens one for every four or five users registered. And it seems to only be when they register for a Forum Id, not register with Facebook, Twitter or Google+. Only one email for those.

On my forum. It is running 2.0 RC1.

Fixing the duplicating mails issue is still complicated. issue hunt continues :evil:

And to the YAF team - thanks for having another go at this issue, since it is quite annoying for users at times...

Did you actually have any Moderators? If you have the team page enabled it lists all moderators.

I'm Admin on my site and it only sends an email to Moderators. I just confirmed this.

Why doesn't it email Admin?