What is IMAP?
IMAP (Internet Message Access Protocol) is a standard protocol for accessing email that keeps messages stored on the server, allowing you to read and manage email from multiple devices with synchronized state.
IMAP (Internet Message Access Protocol) is the modern standard for accessing email from mail servers. Unlike POP3 which downloads emails to your device, IMAP keeps messages on the server and synchronizes state across all your devices. Read an email on your phone, and it's marked as read on your laptop too.
How IMAP works: 1. Your email client connects to the mail server (typically on port 993 for secure connections) 2. You browse emails stored on the server—they're not downloaded by default 3. Actions you take (read, delete, move to folder) are synchronized to the server 4. Other devices see those changes when they connect
IMAP is essential for modern email usage where people access the same account from phones, tablets, laptops, and web browsers. It supports folders, flags, and search directly on the server.
Why IMAP Matters
For email senders, IMAP matters because it's how recipients access the emails you send. Understanding IMAP helps you debug delivery issues—if your email was delivered (confirmed via SMTP logs) but the user can't find it, the problem might be IMAP sync or folder filtering on their end. IMAP's folder system is also why emails sometimes land in unexpected places like Promotions or Updates tabs.
How Ark Handles IMAP
Ark focuses on sending transactional email via API and SMTP, not receiving. However, understanding IMAP helps when debugging 'I didn't receive your email' issues. Ark's delivery logs show successful SMTP handoff; if the user still can't find the email, IMAP sync delays or client-side filtering are likely culprits. Our detailed event tracking helps isolate whether issues are send-side or receive-side.
Frequently Asked Questions
What's the difference between IMAP and POP3?
IMAP keeps emails on the server and syncs across devices—read an email on your phone, it's marked read everywhere. POP3 downloads emails to one device and typically deletes from server. IMAP is better for multi-device access; POP3 is simpler but outdated for most use cases.
What's the difference between IMAP and SMTP?
SMTP sends emails; IMAP retrieves them. SMTP is outbound (your server to recipient's server). IMAP is inbound (recipient accessing their mailbox). They're complementary protocols—SMTP delivers the letter, IMAP opens the mailbox.
What port does IMAP use?
IMAP uses port 143 for unencrypted connections and port 993 for IMAPS (IMAP over TLS/SSL). Always use port 993 for secure connections—port 143 should only be used with STARTTLS upgrade.
Why would someone use IMAP for programmatic email access?
Developers use IMAP to build applications that read incoming emails—support ticket systems, email parsing services, or monitoring delivery confirmations. For most use cases, webhooks (like Ark's inbound webhook) are more efficient than polling via IMAP.
Related Terms
SMTP
SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending emails across the internet...
Email API
An email API (Application Programming Interface) allows developers to send, receive, and manage emai...
MX Record
An MX (Mail Exchanger) record is a DNS record that specifies which mail servers are responsible for ...
Ready to improve your email deliverability?
Ark handles imap and more automatically. Start sending in 5 minutes.