Outbound Voicemail Detection and Line-Type Call Filtering

v26.7.16

Published: July 16, 2026

This week's update to the Syllable Agentic Platform adds an outbound voicemail detection mode that navigates automated call screeners and leaves messages on voicemail greetings, plus a rule editor that filters outbound campaign calls by line type, carrier, and country code. It also makes Responsive Dialogue always on for channels and cleans up prompt saving.

Campaigns

• Added an outbound voicemail detection mode that navigates automated call screeners and leaves messages on voicemail greetings so that agents can complete more outbound calls without human intervention.
• Added a rule editor to outbound campaign configuration that filters calls by line type, carrier, and country code, replacing the previous line-type filter so that campaigns reach more dialable numbers while staying within compliance rules.

Channels

• Enabled Responsive Dialogue on all channels by default and removed the toggle, Beta tag, and advanced telephony parameters so that every channel runs the low-latency conversation mode without extra configuration.

Prompts

• Fixed the prompt editor saving stray non-breaking spaces from blank lines and empty list items so that saved prompts stay clean.

Telephony Integration

• Replaced the raw HTTP 400 error shown when a phone number purchase finds no available numbers with a clear, user-friendly message so that the reason is understandable.