Short version: I have a local folder on my Thunderbird account containing almost 12,000 messages imported into it from a .mbox file generated using Google Takeout. I've linked a new G-Suite account to this Thunderbird account and want to import these 12,000 messages into my new G-Suite inbox. Every time I try, about 245 will import and then it stops and will not advance past that. More detail: My personal Gmail account was checking and sending mail for my work account, which was set up on a web hosting server. Because of issues with that web hosting server, I decided to upgrade to GSuite. Because I had about five years of work emails in my personal Gmail account (almost 12,000) and often refer back to them, I wanted to get those emails into my new GSuite server. I sorted them all into a label I named "Work" and used Google Takeout to export them into an .mbox file. I then downloaded and installed Thunderbird, uploaded that .mbox file into a local folder in my Thunderbird account and configured Thunderbird to import/export to my work email address on the GSuite server. That all seems to be working fine, but every time I try to import the contents of the local Thunderbird folder containing my 12k work emails into my work email address that's connected to Thunderbird, it only moves about 245 of them. Any thoughts on what I could try are so appreciated. Thank you!