Deliverability glossary · Updated 2026-10-27
AI SDR
Also called: AI sales development representative
An AI SDR is software that does the prospecting work of a sales development rep: finding people who fit your ideal customer, writing to each one, sending and following up, then handing interested replies to a person.
The label covers tools that work in very different ways. FirstSales sends from mailboxes you connect and Raechly from senders it sets up on a domain bought for you alone; both charge credits per action. Explee sends from inboxes it owns and charges per email. Gojiberry watches for buying signals and messages people on LinkedIn. The job is the same; the risk is not.
The first question to ask is whose reputation the mail goes out under. Mail from your own domain builds a history you keep. Mail from a vendor’s inboxes builds the vendor’s, and the fast start you get on day one is borrowed from it.
The second is how much the agent does without asking. Full autonomy is quick, and reviews of autonomous tools are full of campaigns that started before anyone approved the list. A middle ground that works is an agent that drafts per person and holds each draft until someone says yes.
Treat published reply and placement rates with care. Most come from the vendor’s own tests, without a sample size or a method. Your reply rate on your own list over a few weeks is the only number that carries over to your business.
How Raechly handles it
Raechly finds people who match an audience you confirm, writes one email per contact from your company profile and the product you picked, and sends nothing until you approve the real emails. An interested reply opens a deal, and Claude or Cursor can drive the whole loop over MCP.
Related terms
Buying signals
Buying signals are actions suggesting a person or company may be ready to buy, such as engaging with a competitor, visiting your pricing page, changing jobs, hiring for a related role or raising money.
Email warmup
Email warmup gradually increases sending from a new mailbox while generating positive engagement, so mailbox providers build a reputation for the address before it sends cold volume.
Sending reputation
Sending reputation is the trust score mailbox providers assign to your domain and IP based on complaint rate, bounce rate, engagement and authentication history.
Back to the full deliverability glossary, or read how these pieces fit together in how Raechly protects deliverability.