Log onto your account online. There you will see what messages are available. If your account was POP and set to delete after download, those messages are lost.

Hi David. I have seen my most recnt emails on the server but my older saved emails are not there. I have a bt email account and usually I can see all the old and new messages on the server. I have had to buy and set up a new tower just recently and therefore lost Thunderbird data. Does Thunderbird have a way I can get to my previous emails? Many thanks for your assistance. Freddy

If it was a POP account and you have the old PC, then it's possible to find old messages on that profile. Otherwise, I fear they are lost.

Hi David,

thanks for this. I think I understand. I have IMAP not POP3 so shouldn't the messages be there?

Does this mean my older emails should be on the server? Sadly my old pc seems dead - apparently the motherboard and hard drive won't talk to each other any more.

If the account on old PC was IMAP, they will still be there. Changing from one PC to another would have no effect.