A method for obtaining a size of an Email of a mobile terminal, comprising: extracting a preset standard mail template from a terminal file system, and using the standard mail template as a standard size of the Email; obtaining a size of contents input when a user edits the Email, and obtaining a size of a mail header and a size of a mail body of the Email according to the size of the contents input and the standard mail template; and adding the size of the mail header to the size of the mail body to obtain and display the size of the Email, wherein, the step of obtaining a size of a mail header of the Email according to the size of the contents input and the standard mail template comprises: obtaining a size of input contents of each field of the mail header when the user edits the mail header of the Email; subtracting the size of the input contents of each field from a standard size of a corresponding field of the mail header in the standard mail template to obtain a field difference of each field; and adding the field difference of each field to the standard size of the mail header in the standard mail template, to obtain the size of the mail header of the currently edited Email, and wherein, the step of obtaining a size of a mail body of the Email according to the size of the contents input and the standard mail template comprises: obtaining a size of text contents input by the user and/or a size of an attachment inserted by the user when the user edits the mail body of the Email; extracting a standard size of the mail body in the standard mail template; and adding the standard size of the mail body to the size of the text contents and/or the size of the attachment, to obtain the size of the mail body of the Email edited by the user. extracting a preset standard mail template from a terminal file system, and using the standard mail template as a standard size of the Email; obtaining a size of contents input when a user edits the Email, and obtaining a size of a mail header and a size of a mail body of the Email according to the size of the contents input and the standard mail template; and adding the size of the mail header to the size of the mail body to obtain and display the size of the Email, wherein, the step of obtaining a size of a mail header of the Email according to the size of the contents input and the standard mail template comprises: obtaining a size of input contents of each field of the mail header when the user edits the mail header of the Email; subtracting the size of the input contents of each field from a standard size of a corresponding field of the mail header in the standard mail template to obtain a field difference of each field; and adding the field difference of each field to the standard size of the mail header in the standard mail template, to obtain the size of the mail header of the currently edited Email, and obtaining a size of input contents of each field of the mail header when the user edits the mail header of the Email; subtracting the size of the input contents of each field from a standard size of a corresponding field of the mail header in the standard mail template to obtain a field difference of each field; and adding the field difference of each field to the standard size of the mail header in the standard mail template, to obtain the size of the mail header of the currently edited Email, and wherein, the step of obtaining a size of a mail body of the Email according to the size of the contents input and the standard mail template comprises: obtaining a size of text contents input by the user and/or a size of an attachment inserted by the user when the user edits the mail body of the Email; extracting a standard size of the mail body in the standard mail template; and adding the standard size of the mail body to the size of the text contents and/or the size of the attachment, to obtain the size of the mail body of the Email edited by the user. obtaining a size of text contents input by the user and/or a size of an attachment inserted by the user when the user edits the mail body of the Email; extracting a standard size of the mail body in the standard mail template; and adding the standard size of the mail body to the size of the text contents and/or the size of the attachment, to obtain the size of the mail body of the Email edited by the user.