If you upload an EPUB file to the _INBOX or via a direct upload, the MOBI file will be created when the file imports to NetGalley. For _INBOX uploads, please refer to our _INBOX processing schedule.
The KindleGen conversion process duplicates the information within the original EPUB file, which causes the MOBI file to be larger than the original EPUB file. We’ve found that the difference in size varies from file to file. As a rough estimate however, we assume that file sizes are likely to double. If an EPUB file is 2MB, the resulting MOBI file is likely to be approximately 4MB.