When applying for example to a postdoc position, is it appropriate to write the text of the cover letter directly into the email, or should it be attached as a seperate file?
One advantage of stating the content of the cover letter directly in the email I could see is that there are good changes that the potential future employer reads it before opening any other ducuments, such as the curriculum vitae, list of publications, etc that might be attached.
I would advise to make the email brief, and make sure that the motivation letter is the first attachment. Often, motivation letters are printed (at least the ones which wind up in the final round) and a properly formatted letter looks better than a printed email.
It depends who you are applying to. Often the recipient e-mail is not the Principal Investigator (PI) themselves, but a member of the admin staff who pre-checks the application and prints the documentation. In that case a separate file would be better, and the e-mail would just state that the application letter and CV are attached.
However, if the application is being made directly to the PI themselves, I would be inclined to place the application text in the e-mail itself.
On a side note, always use PDF for documents to make sure that they will print and display exactly as you see them regardless of what OS or software that the recipient is using.
