Samsung t229 blinking icon on top of phone and its a closed envelope with a blue phone icon on top of it blinking. What is it? No unread messages and nothing in outbox pending. After I delete my inbox it disappears.

SOURCE: envelope sign stuck

dear brother the solution for ur prob is
actually your sim card memory is full, that's why the sign of msg memory full flashing on your cell screen.
delete 1 or more than one msg from ur sim card memory.

best regards
good day,
Anwaar

SOURCE: voice mail icon

highlight the message in your inbox and press menu. You should have the option to unlock. Select that. tHen you should be able to delete them.
As far as your voicemail...
Call and leave yourself a message and then delete it. This will cause the voicemail system to send a message to your phone to remove the icon.

SOURCE: Text Message Icon in Toolbar and no new messages

erase your inbox and it goes away.

SOURCE: i have a flashing message icon......but my inbox,

this usually happens if your memory is full.try deleting some messages and then turn off and turn on the phone.hopefully it wud be solved