IMAP Upload is described as 'tool for uploading a local mbox file to IMAP4 server. The most stable way to migrate to Gmail' and is an app in the OS & Utilities category. There are nine alternatives to IMAP Upload for a variety of platforms, including Windows, Linux, Online / Web-based, Mac and iPhone. The best alternative is MailStore. It's not free, so if you're looking for a free alternative, you could try imapsync or OfflineIMAP. Other great apps like IMAP Upload are audriga Email and Groupware migration (Paid), ShuttleCloud (Paid), mnIMAPSync (Free) and MigrationWiz (Paid).
OfflineImap synchronizes email between an IMAP server and a MailDir or between two IMAP servers. It offers very powerful and flexible configuration options, that allow things such as the filtering of folders, transposing of names via static configuration or python scripting.
By using the Audriga migration service you can move your email accounts and groupware accounts including emails, contacts, calender data and tasks and easy, fast and secure to your new provider. No software installation is required.
MigrationWiz provides on-demand mailbox migration services through a fully automated cloud-based solution that can be accessed at anytime from anywhere to perform a seamless mailbox migration on demand.
Softaken IMAP to IMAP Migration allows transfer of emails from one IMAP Server to another. All IMAP Servers are compatible with this application. Users can easily migrate complete mailbox folders between IMAP Server accounts with attachments.
Softaken IMAP Mail Backup Tool is designed to export IMAP Server emails to local PC. With this application, you can export cloud emails to PST, EML, EMLX, MSG, MBOX, HTML, MHTML, and PDF formats. The software supports saving of all cloud-based application emails to local PC.