APPEND could not retrieve literal argument: This error is caused by a well-known bug in the IMAP implementation used by your email server. This typically affects IMAP servers known as SmarterMail.
MigrationWiz attempts to create items at the Destination the fastest way possible. To maximize throughput, MigrationWiz leverages IMAP fast create mode. In fast create mode, MigrationWiz pipelines item creation commands to provide significant speedup. Most systems do support this mode of operation, but not all.
Upgrade Your IMAP Server
Consider upgrading your IMAP server to a newer version with improved handling of IMAP Fast Create mode.
Disable Fast Create mode
If your IMAP server cannot be upgraded, the following workaround can be used:
1. From the MSPComplete dashboard, click on All Products.
2. From the overall project list, select your project OR select your customer from the All Customers drop-down list, then select your project.
3. On the MigrationWiz project dashboard, click on Edit Project.
4. Under Support > Support only options, enter MustWaitAfterLiteral=1.
5. Click on Save.