How can I change the size of received emails?

I have Classic and the font size of my received email is very small, how can I change the font size so I can read them

how do I change the time zone when emails are received? I"m receiving emails that does not list the actual time sent or received but some other time and I'd like to know the actual time the emails are being sent to me.

I was reading email this morning using Firefox 5. I did something to cause the font size to change to the smallest possible size. I can't figure out how to get it back to a readable size. Any and all ideas will be appreciated.

A company sends me emails that I need to save. I would prefer to change the subject line to make it more useful to me. Other than forwarding every email to myself with my customized subject line and then deleting their original email, is there a way...

All my emails that I get are all small. I would like to change the text size.

the text in the heading and subject line are larger, but I don't know how to do that in my exmails and make it stay that way without having to change it everytime I write an email.

The print looks normal in the e-mail, untill I print it. Then the text becomes very small (about size 4) and is in the upper left side of the page. How do I get it back to normal size, and the text centered again?