Group Voicemail (spoiler alert >>> WHY IS IT NOT FIXED <<<)


Hi, i thought i would post this here.

Group Voicemail still isnt working, i opened a ticket in 2015, i then opened another ticket (20181010122530) referencing that ticket from 2015 as it still wasnt fixed, i then keep posting in the firmware upgrades that it wasnt fixed

Today (2020), its still not fixed, so heres the issue

I have clients telling me they HAVE to have it, it works in FreePBX, Sangoma, Cicso, frankly in every online PBX, so why hasnt Grandstream fixed this, i have clients telling me they are buying back in to FreePBX with Sangoma as there call center MUST have group voicemail, there are work arounds but its real complicated and now limited to 10 phones (max registraiton per extension).

This is real basic lads:

  • How do i register the phone to GROUP VOICEMAIL extension to receive MWI
  • How to i change the welcome greeting in Group Voicemail

Its not rocket science, its in Asterisk already, it always has been !!!


try this:

  • create dummy voicemail (example 299)
  • register 299 as account 2 in the phones concerned
  • record the temporary message in box 299
    If you receive messages on 299, display it on all extensions. You can also create the voicemail button 299 to query the box.
    You just have to be careful that if one of the extensions reads the messages, it stops notifying the others (which in my opinion is better).

I think that’s the best thing.
It’s another matter, but in my opinion GS should make it easier to read msg from outside the company (as you say all the other competitors do it too).


You may be able to change the greeting based upon this thread -


Ive been doing that for 5 years, i was the one who wrote the instructions for this work around about 4-5 years ago.

That works very well as a workaround, however why is there even a work around needed, the PBX has GROUP VOICE MAIL in it, why would i need a work around?

So to explore this further:

  • Its not possible to deploy this “work around” past 10 endpoints as each extension will only allow up to 10 concurrent connections, so in a call center of 20-50 extensions which is super reasonable as the 6510 can support 2000 extensions the PBX is not usable due to a limitation of a feature that was never completely deployed correctly. However in other brands using the same engine it fully works

Group Voicemail in the system might be there, but its bugged as it is…

  • How do i change its default greeting?
  • How do i delete voicemails it received and sent out to other extension (it does fill up, it IS a voicemail box itself (as it should be by its design))

Group Voicemail item was designed to be LOGGED IN TO DIRECTLY to be managed, thats what its whole point was in Asterisk, Grandstream just never finished its design / deployment.

I no longer argue with clients about it, if they need, they go off and buy Sangoma (normally removing the Grandstream PBX), ive waited 5 years, had tickets open about it, posted many messages on here about it, and on a lot of Beta released. The amount of money ive lost due to Grandstream shooting there own hardware in the foot is astounding…

  • Changing phone default firmware protocol from HTTPS to HTTP so the PBX can no longer send a firmware to the phone AND making it LESS SUCURE (also theres no setting in the PBX to allow you to select HTTP as a firmware protocol, why would there be, ITS LESS SECURE !)
  • Unable to deploy a firmware over an openVPN line, so it bricks the phone needing a manual cable pull (ive had to FLY to other countries to fix this AT MY COST)
  • Group Voicemail box that cant actually accept ANY phones to log in and see a MWI indicator in that mailbox
  • A Group Voicemail box that has no way of creating a greeting
  • A Group Voicemail box that has no way of getting the messages that are left in it

Ive dedicated hardware to them to resolve some of this stuff (a huge Watchguard openVPN server to get the openVPN working in the GCP21xx phones)… I name a few but there are many giant “drop ball” situations, it just simple, fix the stuff in the system, dont break it when deploying new toys…



Sorry, was not aware that you developed the workaround; only trying to provide a solution (no matter how unsavory) to one of the questions presented.

As a user, I have no more control or influence over GS than you, so really have nothing to offer.



The work around “was” good, when i found it, there was no 10 connection limit, that only came at a later firmware.

The main drawback is the need to assign the endpoint a redundant extension, which itself creates other issues with regards call hold, call waiting and other minor problems which i wont go into here.

The reason for posting here is to raise awareness and get it fixed.

The fix is a setting on the phone “Monitor Voicemail” with a setting = [group voicemail box number], that would fix it, unless they removed it from Asterisk (i assume not as Asterisk is openSource) then it would work from the phone, its just need incorporating in to the PBX to allow that P code setting to push to the phone from the GUI on both 61xx AND 62xx as this bug has been around since 2015 that i know of.

On most systems a BLF would be assigned *98[mailbox] and that would subscribe you to the MWI, when a message arrived the MWI would light, pressing the button accessed the voicemail box… *98[mailbox] works on Grandstream to access the Group Voicemail box itself, but doesnt work for the MWI light as a BLF


I withdraw that part of the problem, greetings can be changed on the Group Voicemail page in the PBX, so that works, any other issues with be resolved once the phone can “Monitor Group Voicemail” as when listening to the messages you can then delete / manage them, which will also clear the MWI from ALL phones that are monitoring that voicemail box.

Whats ironic is the Group Voicemail screen has a “password” box, what would this be for? as you cant monitor it directly at the moment, so kinda pointless…


Hello @SFX_Group

Just going through the list. Entirely out of ignorance as I haven’t run into many of these issues. I still thing the group voicemail implementation on GS is weird but, I might address my complaints at the end.

Maximum number of people in a group. I just added 96 extensions to a test group. That the largest customer I’ve got so, I couldn’t test more. I was not able to test if all 96 phones would actually ring. So, if you’re having the same issue, I’d like to know. If your issue is that the software wouldn’t let you add the extensions to a group vm, well, that might be resolved.

Default greeting. I think you’ve acknowledged that you can dial *98, enter the group VM, enter the password and update the recording. So, I’ll leave this.

Delete Voicemails that have been put in boxes. YES YES YES!!!, I’m 100% in agreement with you. This is basically a non starter as someone has to log in once in a while to delete them manually. 7,6,7,6,7,6,7,6,7,6,7. It’s not actually hard and you can clear about a hundred messages per minute. Still, come on GS.

Had to fly to powercyle equipment… This is a budget device that you can log into the flip the switch remotely. I know, you couldn’t have know in advance and GS should just make equipment that works. However, I come from a Mitel background and, if you ever want to meet a group of people who really and truly think their P00P don’t stink, go to a Mitel event. I learned about the IP power bars due to the need to remotely reboot gear that I’m told shouldn’t need rebooting.

I don’t fully understand your point about the watchguard. Are you expecting the UCM to manage the connection? watchguard is great for openVPN because it has the processor overhead and memory to support huge numbers of connections, well, the right sized watchguard anyway. I probably just misunderstood your point but, I’d love to understand if you feel like restating.

Regarding the fix. Right now, this is tested by me. If my extension is assigned to a group voicemail, and a message is left, the system will put that group voicemail in my extension VM and turn on the message waiting light. If I press the message button and press 1, the system will play back messages. If the message came from a ring group, it will tell me which ring group number only. It does not tell me the group voicemail but, basically, I don’t see that as an issue for me, with my system, the group voicemail matches the ring group. So, my sales ring group goes to my sales group voicemail. I’m not sure how long this feature has been around but I tested to confirm right now and it’s working. I’ve got a couple ring groups, so, I’m going to make a little printing out with each ring group number and the name of the ring group for easy reference.

Still, I cannot confirm the maximum number of extensions the system will ring, even though I could add 96 extension to the ring group and it’s exceedingly frustrating that there isn’t a check mark box or some easy way to tell the system to delete the message after it’s been moved to the associated VM boxes.


Sorry, I forgot to address that question.

That’s the password you use to log in to the Group VM.

Dial *98
Dial the Group VM extension number
Dial that password


The maximum was referring to the work around, unless you have managed to get extension to see the voicemail group itself and not there own voicemail the group copies the voicemail to?

From how i understand it you now have 96 copies of the same voicemail in 96 extensions, resulting in the possible return call of that one caller 96 times, this is not acceptable in any call center.


It seems to me, the whole situation is just flawed. I know I’m getting off topic a little.

Hypothetical speaking, if I were in the position of actually running the company, I wouldn’t ever have more than a handful of people who get the vm’s through email only. Again, it would be great if the group vm could delete automatically but, whatever. The email would be sent to the inbox of the lead hands. All the lead hands would monitor their email and have a second account setup for vm’s. Under the second inbox, there would be a number of subfolders, one each for each lead hand. Whichever lead hand sees the VM drags it into their subfolder, then process it as is appropriate. Call the customer back, forward the VM to another staff member, whatever works.

I know I can’t force a business to change if they want / need a certain outcome, and it would be nice to have more tools. Now that you’ve brought this up and I poked around a little more. When a customer brings it up again, I’m going to recommend skipping the actual group voicemail, using a single extension as has been recommended. Sending out email as I’ve just outlined, and deleting the VM after email. It seems it will be easier to coordinate and control emails rather than vm’s anyway.


The whole point of “group voicemail” was a single box, MANY phones see with a MWI, so you had 300 phones all looking at that ONE box, when ANY phone listened and deleted the voicemail all 300 phones MWI went out, as it was a single box.

Its a GREAT feature, it works in every single PBX ive seen just not Grandstream and whats odd is ALL the functionality is in the PBX (voice prompts on the webpage, email, pin code) the only thing NOT working is “Monitor voicemail” in ANY phones, so they cant point at this single Group Voicemail box.

They dropped the ball, as its clear that was its design, then they added a feature, the “push voicemail to other voicemail boxes” which other systems dont have, they dont have it as no one uses it as you have 300 copies of the same voicemail, the caller who left the voicemail then gets 300 people calling them back !

The work around only works for 10 extensions, as you can only ever have up to 10 end devices logged into a single extension at any one time, this limit was imposed after i posted how to get around the issue (many years ago), that would allow 10 phones to share a single “group” mailbox.

You could still use group voicemail and just push the email out as you said, the worry with this is if the email doesnt arrive you have lost the voicemail (if you set it to delete).


Thank-you for your thoughtful discussion.

I understand your comment on emails disappearing as it’s certainly happened.

However, I’m convinced that your desire to have many people, upto hundreds, monitor a VM box, with everyone able to login and potentially delete messages, even if the message has not in fact been followed up on. Keeping in mind, there is no way (that I know of) to recover deleted messages or find who deleted a specific message. This process of many users monitoring a single VM box increases entropy exponentially.

My thoughts aside, I do agree that group voice mail, as implemented by GS, is unsatisfactory.


Call centers have been run this way for many years, ive set them up 20 years ago… generally the manager got an email, 20-30 workers had access to the same box, theirs a whole system in place for that… the fact is Grandstream system does not work the same as other PBX’s which means its not a drop in replacement, ive seen clients move over to Sangona based on this.

Grandstream has to be the same as others PBX vendors as the clients workflow will not change based on the PBX flaws, they just wont buy it and ive seen them move away from it, they will go for another brand thats “standard”, espcailly when “upgrading”, ive removed a lot of FreePBX, only to be stopped in my tracks with the below:

  • No Group Voicemail
  • Unable to send emails to more than a single email address
  • No built in VPN (this one i understand and work arounds are solvable).

All of the above needs large work around to the point they just stop looking at the hardware.


openVPN is not a standard, infact its nothing, only a “great idea”, so a device that says “openVPN” being a client (phone) and a server (firewall) having openVPN does not in anyway at all mean they will work together.

The UCM does not have an openVPN server in it, it should do, but doesnt, mostly as it would eat through CPU time with the encryption, so its offloaded, thats all well and good, but if the VPN server is not your main firewall, your creating routes in the PBX to get that traffec from the openVPN server.

I am a partner and sell watchguard, so i have access to some real large firewalls, i requested Watchguard support Grandstream phones, so the back end people meet up and make it happen, however it needs testing, so i allow access to my Watchgaurd firewall, and its working… so now a perimeter firewall does the VPN with no messy routes needing to be added to the PBX.

There are other issues with the VPN through the Watchguard, the phone appears to hang every 4-6 days needing a hard rebooted (UI not working), so not sure whats going on there.


I have a client which runs a call center. There are about 30 agents and scenario is that when the business is closed, in the old system, the caller could leave a message in a shared voicemail. Once agents would come back to work, every agent would have the MWI and the first one that would take the message could delete it.

So, since i installed and UCM6204, i don’t have any solution for this. And the “voicemail copy” solution is a joke… So for now, i have no solution for this, unless an obscure one i didn’t find already… So if anyone has the solution, PLEASE SHARE IT !!! My client are just flabbergasted i can’t come up with a solution for such a basic need…


Had the same issue, had a ticket open for 5 years for this problem…

Whats ironic is the “Group Voicemail” does actually work like this, the only thing you cant do is subscribe to the Group Voicemail box for the MWI… It does store messages, you CAN call it, listen to them and delete them as a single mailbox, the only thing the phones (and PBX) will not do is allow endpoints to subscribe to see the MWI for that single group voicemail box.

So you could tell them to call that mailbox to find out if there are messages, its just the MWI doesnt work on the phone for it.

I have again brought this to the attention of Grandstream who say they are working on it.

I do have a work around, but it only works for 10 extensions… so wouldnt work in your situation.


Anyone had any updates on these? I’m beginning to question how useful the voicemail group is? It’s more just a voicemail broadcast system than a shared mailbox.

  • It fills up with voicemails no one can see,
  • every member gets a copy and reading it does not mark it read on everyone else mailbox…so potentially the poor person that leaves a message gets multiple call backs.
  • The voicemail group access code doesn’t seem to be any different to the ext. voicemail code … goes to the same place? (*97 and *99)
  • You cant individually set it to delete the voicemail on delivery to email like an extension.

A shared mailbox is very useful … but it has to work.


@RichardW this is a user-to-user support forum for the most part. To get enhancement or bug reports to Grandstream’s attention, please open a ticket at


The reason for this is Grandstream used the Group Voicemail part of Asterisk but for what ever reason has not allowed “Monitor Voicemail” in any of there phones, so your unable to monitor that “group voicemail” box… thats the only part of the system not working as expected.

>>>> Ive had a ticket open for 5 years for this to be fixed <<<<