Best IMAPSize Alternatives & Competitors in 2025

Console-based utility for migrating IMAP mailboxes.

Open Source

mnIMAPSync - Java IMAP email syncing tool

MigrationWiz provides on-demand mailbox migration services through a fully automated cloud-based...

mbsync is a command line application which synchronizes mailboxes.

The Fetchmail Project

IMAP Upload is a tool for uploading a local mbox file to IMAP4 server.

WholeClear Mail Migration Tool is a brilliant software to migrate emails from one IMAP account to another IMAP account by correct login details.

Free Trial $99.0 / One-off

MailStore Home - A 100% free single-private-user desktop solution

Shoviv presents the best GroupWise to Office 365 migration tool, helps to migrate from GroupWise to Office 365, Outlook PST, EML, MSG & many more.

paid Free Trial $449.0 ($449 for 100 system, $949 for Unlimited System)

OfflineImap synchronizes email between an IMAP server and a MailDir or between two IMAP servers.

Open Source

Easily migrate your email, contacts, calendar items and tasks to your new provider or server. No software installation is required.

Official website for getmail version 5, an extensible mail-retrieval program with support for POP3, IMAP, SDPS, SSL, domain mailboxes, message filtering, and other features.

Backup the emails in your Gmail account.

Open Source