Most e-mail is strictly text oriented. There should be little reason to worry about getting a virus through a text-only e-mail. But, if the e-mail contains a file attachment, then the possibility is there that the attached file may contain a virus.
The best thing to do is to treat any file attachments that might contain executable code as carefully as you would any other new files: save the attachment to disk and then check it with an up-to-date virus scanner before opening the file.