Disable voicemail for line 1

[simonbr]

I have a T54w configured with 2 lines. Line 1 is an extension and it does not have voicemail configured. Line 2 is an extension that does have a voicemail configured to it.

I am using a Yeastar S50 system and the feature code for voicemail is *2. When line 2 has a voicemail, the phone shows the notification and I am able to press the envelope to get the voicemails. When there is no voicemail and I want to go to the mailbox to view old messages or changes options like my greeting, it doesn't work. The phone asks me to enter a code for line 1. The only way I can get it to work is by entering *2 as the code, which when pressing will bring me to the general voicemail prompt asking me to enter an extension then a password.

I would really like to be able to just assign envelope to line 2 only and tell the phone there is no mailbox for line 1. Is there any way to do this?