How can I download email attachments only when requested? The default email application seems to be downloading email attachments when I try to read an email.

I don't want to download attachment by default, it should on request. I should be able to read the mail body text without needing to download the attachment.

I am using my own POP3 server and not GMail.

Is there any way to enable this or another application which I can use for this?

I have Samsung Galaxy Ace Model GT-S5830.
K-9 Mail does load attachments only on request. But your problem is not only the Client, it's more the protocol used for retrieving E-Mail: POP3 does not support the partial download of an E-Mail without their attachment(s), whereas IMAP does. Besides of that IMAP has some nice extensions when it comes to mobile usage: Lemonade Profiles