I have about 13,000 messages in a Gmail inbox, and would like to switch to a system of archiving messages once they're dealt with, rather than using read/unread status.
I know how to do this via webmail, but then, I usually use Thunderbird for Gmail. Is there any advantage to performing the operation via webmail or via Thunderbird? Which will take the least time for Thunderbird to work through in the end to get them sync'd up?