For PSTN calls the voicemail FROM address is not RFC-compliant, and Microsoft advises third-party mail filters to evaluate the P1 sender address instead.
Checked 2026-10-02
- Vendor
- Microsoft
- Product
- Microsoft Teams Phone
- Subsystem
- Cloud Voicemail delivery
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Voicemail Messages Aren't Delivered in Teams or Skype for Business Client — Microsoft · tier 2 current vendor documentation · Resolution for Symptom 1 > Third-party email systems
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting Teams Phone voicemail that is not reached or not delivered: source note teams-voicemail-troubleshooting-third-party-p1-sender. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-voicemail-troubleshooting-third-party-p1-sender
BibTeX
@misc{warmtransfer-claim-teams-voicemail-troubleshooting-third-party-p1-sender,
title = {Troubleshooting Teams Phone voicemail that is not reached or not delivered: source note teams-voicemail-troubleshooting-third-party-p1-sender},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/teams-voicemail-troubleshooting-third-party-p1-sender},
note = {Source note teams-voicemail-troubleshooting-third-party-p1-sender, checked 2026-10-02}
}