Hive
Hiring
What they do:
Marketing automation for event promoters (email, sms, ads, CRM)
Quick facts:
Top Email Startups
This list has 27 startups and was last updated on Oct 15, 2026. 5 of them are hiring right now. Biggest hubs: San Francisco (12) and London (2). Largest teams: Hive, Mailgun, and MailTime.
27 startups
MailTime
Hiring
What they do:
Emails as quick and easy as text messaging.
Quick facts:
HQ: Hong Kong
Zaymo
Hiring
What they do:
Zaymo is building an AI marketing agency
Quick facts:
HQ: Lehi, UT, United States
AgentMail
Hiring
What they do:
Email Inboxes for AI Agents
Quick facts:
HQ: San Francisco, CA, United States
Compose.ai
Hiring
What they do:
Cut your writing time by 40% with AI-powered autocomplete
Quick facts:
HQ: Carlsbad, CA, United States
What they do:
Prevents your emails from landing in spam.
Quick facts:
What they do:
Email sending for software companies
Quick facts:
HQ: Washington, DC, United States
What they do:
Managed Sales Email Delivery For Cold Outreach
Quick facts:
What they do:
The platform for enterprise AI agent automations, starting with email.
Quick facts:
HQ: San Francisco, CA, United States
What they do:
The AI Assistant for Gmail
Quick facts:
HQ: San Francisco, CA, United States
What they do:
Cursor for Email
Quick facts:
HQ: San Francisco, CA, United States
What they do:
Your email assistant because you deserve a better morning
Quick facts:
HQ: San Francisco, CA, United States
What they do:
Execute the best sales playbook in industry
Quick facts:
HQ: San Francisco, CA, United States
What they do:
Persistent email inbox, phone number and secret storage for agents
Quick facts:
HQ: London, United Kingdom
What they do:
The email API built for product teams
Quick facts:
HQ: United States
Mailgun
Acquired
What they do:
Email API service.
Quick facts:
HQ: San Francisco, CA, United States
Posterous
Acquired
What they do:
Dead simple blogs by email
Quick facts:
HQ: San Francisco, CA, United States
Rapportive
Acquired
What they do:
Add profiles to email.
Quick facts:
HQ: San Francisco, CA, United States
ZeroMailer
Acquired
What they do:
Easy mailing lists
Quick facts:
Polymail
Acquired
What they do:
Email productivity platform for business.
Quick facts:
HQ: Marina del Rey, CA, United States
reMail
Acquired
What they do:
Email search for iPhone. Acquired by Google in Feb 2010.
Quick facts:
HQ: CA, United States
Forage Mail
Shut down
What they do:
AI that solves email overwhelm. Not another mail app.
Quick facts:
HQ: New York, NY, United States
Glider
Shut down
What they do:
We filter distracting emails away from your inbox.
Quick facts:
HQ: Portland, OR, United States
Zenbox
Shut down
What they do:
Brings dozens of SaaS's (Mailchimp, Stripe, Shopify, Salesforce,…
Quick facts:
HQ: San Francisco, CA, United States
Threadable
Shut down
What they do:
Mailing lists 2.0. Threadable makes group email less noisy and more…
Quick facts:
HQ: San Francisco, CA, United States
Slik
Shut down
What they do:
Slik automates your sales.
Quick facts:
HQ: San Francisco, CA, United States
Post.fm
Shut down
What they do:
New email inbox.
Quick facts:
HQ: London, United Kingdom
Questions and answers
How many startups are on this list?
There are 27 startups on this list, last updated on Oct 15, 2026.
Which of them are hiring?
5 of them are hiring right now, including Hive, MailTime, and Zaymo.
Which of them have the largest teams?
By team size: Hive (65 employees), Mailgun (51 employees), and MailTime (18 employees).
Where are they based?
The biggest hubs are San Francisco (12) and London (2).