I have a customer with a Vodavi Sts phone system with voicemail. After voicemail answers, it plays the greeting and says press 1 to order a t-shirt. He wants all the phones to ring after pressing 1. Is this possible?

Yes it is. The most effective way would be to have digit 2 (1 should be reserved as the first digit of extensions) go to a ring-all hunt group. So press 2 (or 1) to group say 451 which has all extensions as members. The ring-all group is created in phone system admin programming (flash 30) and you would have to program the voice mail ccr/auto attendant as well with a pc.

Thanks for your help. Can I still send it to voicemail after all the phones ring? (Say after 6 rings)

Sorry, I think your request got lost in the holiday craziness.
STS Hunt groups can only overflow if all members are busy. You could use a virtual extension for ringing and make it time out to voice mail. Then assign the virtual extension onto all phones that are to ring.

How do I set up a virtual extension and assign it to the phones that are ringing in the hunt group?

Flash 50, page B, button 1. Your entry would be 9 to mark a station as virtual. Then, put call coverage buttons on all of the other phones for that virtual extension.

When a caller calls my customer, the auto attendant answers and instructs them to press one or two. After that they are sent to extension 102. If no answer after 5 rings, it goes to voicemail. Can I put a option, say press 3 in the auto attendant and have it go directly to extension 102 voicemail?

The flash based voice mail is pretty basic. You can transfer to an extension, go to another ccr menu or play a greeting. To get option 3 to a mailbox, you would have to set three to go to its own virtual extension that is forwarded immediately to voice mail 440. You set this up in the phone system itself by setting the virtual extensions vmid to 102 and all call forwarding the virtual extension to 440.