Blocking "unknown" callers from voicemail

[2nick]

I couldn't find a category relevant enough to put this topic in, but I'm on pay as you go, so it's the nearest category I could guess.

I've blocked "uknown"/withheld callers from phoning me on my phone, however, that doesn't stop the voicemail service from enabling them to leave a message.  It seems to block other people in my block list (or perhaps it doesn't even do that, but no blocked callers have left voicemails), just, that one obstacle, completely blocking unknowns yet keeping my voicemail activated for known callers.

I don't even think there's an option on the 901 voicemail service for blocking unknown callers and realise that numbers blocked on my phone aren't necessarily communicated back to the network, but if that's the case, then even people that have been blocked would be able to leave voicemails.. I wonder how this all works technically.

But basically, I'd just love to block unknown callers completely.. is there a way to do this?

[2nick]

Thanks for this.. ok.. it's a GT-S5260 (it says on the sticker and quite stupidly of me, it tells me what the phone is in big letters when it boots up).  Having said that, my phone physically looks different to ones I see pictures of but I guess it's the same model functionally.

Am I right though in guessing the make and model of phone isn't related to o2 voicemail? - for example, regardless of what model the phone is, when I had it switched off, it would be o2 that are still storing those voicemails on their system and their network, then sending them to me via the 901 system when I next switch the phone on.  This to me indicates that regardless of what phone you have, if you're using o2 voicemail, they are enabling anonymous callers to leave voicemails and there appears to be no option to stop this from happening.

Am I right here? or can some models of phone instruct the o2 network to use extra options?.. and if that's the case, wouldn't these options be on o2's 901 menu?.. I admit I haven't checked their menu in the last year or two but in the past remember there being no option to stop withheld callers from leaving messages.

Is the phone relevant?

[2nick · Accepted solution]

I just did an experiment here and discovered that even if I block a known number (my landline number in this case), o2 voicemail STILL goes ahead and lets me leave a message.. I'm just wondering if there's any way o2 could add some part to their service that enables the customer to upload numbers that don't want to be heard from, including a general "block unknown callers from voicemail" option.

How would I go about suggesting this to o2?.. just wondering if anyone out there knows.

Thanks for all the replies