VMblast memory and extension limits?

Continuing the discussion from VM Blast Group limitation on number of extensions in group:


Can i set up a VM Blast group for 2000 extensions, and how much memory will be needed for this?

Thank you

Short answer is no you can’t.

vmblast passes all extensions as a variable. Variables are limited to 255 characters. with 4 digit extensions this puts you at around 19 members.


I was following the thread/continuing the discussion VM Blast Group limitation on number of extensions in group and it appeared that the limit was 79 extensions and that this was seen as a bug that was fixed. What did I miss?

If we use 3 digit extension will this up the limit?

The change they may have made was moving members to a key/value table. This indeed will let you store unlimited members. These members are still parsed in to a dialplan variable. This is where the limitation would be. As far as I know this is at 255. The format of each extension is EXTEN@default&

Are you sure you are using the right tool for the job? What is your end goal? Though it is completely possible to put a screw in with a hammer it is better to use a screwdriver.


I am thinking you are correct in that there must be a easier way. We want to send a VM blast to 2,000 teachers on an infrequent schedual.

probably better handled by your MTA, look into an “alias” mail address perhaps teachers@yourmta . Be aware that 2000 emails at once might break your agreement with many mail servers, so you might want to throttle your delivery rate, a prime example would be gmail.

If you are using postfix