Voicemail-Voice-Mail | Commonly Confused Words

Voicemail

/ˈvɔɪsmeɪl/

A system that records spoken messages sent over the phone when the person called is not available

This word has no antonyms

/ˈvɔɪs meɪl/

A system that records spoken messages for people who cannot take calls right away

This word has no antonyms

Voicemail and voice mail refer to the same concept but differ in how they are written.
Voicemail is commonly used in American English as a single word.
Voice mail is the two-word form and sometimes preferred in other variants of English.
The meaning does not change between voicemail and voice mail.
Remember that both terms are correct, but voicemail is often more modern and widely used.