I have a receive-only VOIP account with a small-time company in Poland. Not much in the way of support or features, and sporadically offline, but okay. I bought a local DID number from it.
What FOSS Windows or Linux software might I be able to use on a virtual server that
has the ability to auto-answer calls after a timeout of N seconds (or X rings) because I am not picking up the line elsewhere, playback a greeting and record a voice mail,
Optionally, forward the recorded voice mail to an email address.
Better yet, is there a free cloud-based solution somewhere, sparing me the need to deploy this software on my own, having a PC always on?
Maybe some indirect way using eg. IFTTT, such that supplying my SIP credentials in some (web?) client will trigger an email + audio file attachment?