Patent ID: 7373602

Claim:
A computer implemented method of converting text of an electronic mail message to a plain text format, the method comprising: determining that the text of the electronic mail message is in a format other than plain text, the electronic mail message being received by a recipient from a sender; determining, in response to determining that the text of the electronic mail message is in the format other than plain text, that the electronic mail message includes a digital signature; sending, in response to determining that the electronic mail message includes the digital signature, a preview message indicating that the electronic mail message cannot be converted to the plain text format without breaking the digital signature; determining that an email viewer application is configured to only view messages in the plain text format; displaying, in response to determining that the email viewer application is configured to only view messages in the plain text format, a message indicating that the electronic mail message cannot be displayed without breaking the digital signature; receiving, in response to displaying the message indicating that the electronic mail message cannot be displayed without breaking the digital signature, instructions from a user to convert the electronic mail message to the plain text format in order to view the electronic mail message; and converting, in response to the received instructions, the text of the electronic mail message to the plain text format when the text of the electronic mail message is in the format other than plain text wherein converting the text of the electronic mail message to the plain text format comprises converting the text of the electronic mail message and breaking the digital signature.