The system announces, Record greeting. Begin recording after the announcement. The message counter LED displays "- ", and then begins to count down thirty seconds.
When you finish recording, press [greet] again or press [right-arrow]. You will hear a confirmation tone, and your recorded greeting plays back for you.
Answers & Comments
On the base, press and hold [greet].
The system announces, Record greeting. Begin recording after the announcement. The message counter LED displays "- ", and then begins to count down thirty seconds.
When you finish recording, press [greet] again or press [right-arrow]. You will hear a confirmation tone, and your recorded greeting plays back for you.
The above is from page 38 of the manual.