The email infrastructure
for autonomous sales follow-ups.
Developers building sales agents need reliable email primitives — send follow-ups, read replies, manage threads, and label conversations by stage. Mailgent provides the mail API and threading infrastructure so your agent can run multi-step follow-up sequences without human intervention.
API Primitives used
mail.sendSend outbound emails
Compose and send follow-up emails from your agent's identity. Full control over subject, body, and recipients.
mail.replyReply in-thread
Reply to existing conversations to keep follow-ups threaded. Maintains context for the recipient.
mail.list_messagesCheck for replies
Poll the inbox for new messages. Filter by label, sender, or date to find prospect responses.
mail.update_labelsTrack deal stage
Label threads by pipeline stage — interested, demo-booked, closed-won. Your agent organizes as it goes.
Sales follow-ups die when humans forget to send them.
Most deals require 5-7 touches before a prospect responds, but reps stop following up after two. The problem is not strategy — it is execution. Every missed follow-up is revenue left on the table. CRM reminder systems help, but they still depend on a human clicking send.
Developers building sales automation agents need email infrastructure that can send, read, and organize messages programmatically. Mailgent provides these primitives: mail.send for outbound, mail.reply for threaded responses, mail.list_messages to detect replies, and mail.update_labels to track pipeline stage.
How to build it.
mail.sendSend the initial outreach
Your agent composes and sends personalized outreach using mail.send. Each email goes from a dedicated agent identity with its own address and reputation.
mail.list_messagesMonitor for replies
The agent polls for responses using mail.list_messages, filtering by label or sender. When a reply arrives, it reads the content and decides the next action.
mail.replyFollow up or escalate
If no reply comes within your configured window, the agent sends a follow-up using mail.reply to stay in-thread. If a positive reply arrives, it labels the thread and alerts your sales team.
Example prompt
“Check for replies from yesterday's outreach batch. For anyone who hasn't responded in 3 days, send follow-up #2. Label any positive replies as 'interested' and notify the sales channel.”
What developers build.
Multi-step drip sequences
Build agents that execute 5-touch follow-up sequences with configurable delays, stopping automatically when a prospect replies.
Re-engagement campaigns
Build agents that identify stale deals via mail.list_messages, then send personalized re-engagement emails to revive cold conversations.
Meeting confirmation
Build agents that send meeting reminders 24 hours before scheduled calls and follow up with no-shows automatically.
Deal stage tracking
Build agents that read reply sentiment, update thread labels with mail.update_labels, and maintain pipeline visibility without CRM data entry.
Why not use a sales engagement platform?
Sales engagement platforms are closed systems with fixed workflows. You configure sequences in their UI, but you cannot build custom logic, integrate with your own models, or control the sending infrastructure. When you need something the platform does not support, you are stuck.
Mailgent gives you primitives, not a product. mail.send, mail.reply, mail.list_messages, and mail.update_labels are building blocks your agent uses however your logic requires. You own the workflow, the timing, and the decision-making.
Identity isolation
Each sales agent gets its own email identity. Outreach from one campaign never leaks into another.
Scoped access
Agents can only access their own mailbox. A follow-up agent cannot read support tickets or internal mail.
Audit logging
Every email sent and read is logged with timestamps. Full visibility into what your agent did and when.