I want to archive emails by date.

There are a few possibilities depending on how you are currently set up and where you want to archived messages to live. Is this an IMAP account, or POP3? If IMAP, do you want to have those messages accessible on the server so you can get to them using another device? If the answer is Yes... - Create a new folder as a sub-folder of the IMAP account. This folder will live on the email server and an exact, synced copy of it will also reside on your computer; - Sort your messages by year, select everything older than one year, and MOVE those messages to the folder you just created. ---------- If IMAP and you do NOT want those messages to exist on the mail server... - Create a new folder as a sub-folder of LOCAL FOLDERS. This folder will exist only on your local computer. - As described above, sort your messages by date and move the old ones to your newly created folder. If you are moving a large number of messages, it may be safer and more reliable to do it in smaller batches. ---------- If POP3... - Create a new folder as a sub-folder of that POP3 account. Because it is a POP3 account, that folder will necessarily be a local folder. - As described above, sort your messages by date and move the old ones to your new folder.