Ok, I've got to say it, the way that WHMCS handles support tickets, from an admin standpoint, it sucks, quite literally.

A few things I've found (quite) greatly lacking in the system.

Firstly, not everyone wants a "reply" to a ticket that's submitted. Occasionally, individuals will want a silent insert box (sort of like something to catch spam) for pipes.

For example, I'll use what I use things for.
Various systems send mail to me @ a logger address. These systems are sending mail through the SYSTEM commands (ie: no human). Replying to this mail will often result in a looped bounce, as sending mail to root@ system is often disabled, and the bounce is there. Not to mention the fact that most of these mailboxes aren't checked automatically.

Now, it's not that hard to create a silent pipe to do this, in fact I did it in about an hour. However, it's easier if the system that's supposed to handle this (the helpdesk) does this.

Just a thought there.

Secondly,
From the administrative standpoint, individuals should always be able to click on a department, to view tickets in that department (opened or closed), rather than the way that it is sorted now.

Currently (again, using my own setup as an example), there are 10k tickets in the system. Yes, this is mostly due to the 50-100 mails I get from systems and logs and whatnot, but this is still a great deal of mail. The only way to get to the "closed" tickets? To click on a link that will take forever to show up.

Better filtering would stop this problem. For example, searching for client, email, hostname, words in ticket, etc. This would provide a much more accessible setup. Yes, I'm aware that (currently) you may search for client tickets, however, that is only in the current state. So, if you tried searching for John Doe when viewing "open" tickets, nothing would show if he had a closed ticket. If, however, you tried searching for John Doe in "closed" tickets, he WOULD show, however, you'd have to go through ALL of the closed tickets loading just to get to that point.

Thirdly, and this is probably one of the most frustrating things I've seen about this system:

When an email comes in saying "there's a new ticket", can we not have the decency to post at least a ticket link? At any given time I have 10-20 tickets open in the system, so it's quite frustrating to have to go through this without having a clue what's going on here. A link to the ticket, or even better, the RESPONSE in the ticket would be great. Admin should be just as able to respond via email as customers should

I'm not saying that the whole thing sucks, because it doesn't, but there should be some sort of ballance here. The billing side of things (for my needs anyways) is great, and what minor problems have been found, Matt is excellent at fixing. However, from the support side of things, this needs a bit of work