An electronically submitted cover letter should be roughly 250-400 words in length and follow the same general guidelines as a cover letter submitted in paper copy.
When sending a cover letter electronically, whether as an email cover letter or through an online submission platform, you should pay attention to the word count to make sure your cover letter isn’t too long.
The easiest way to do this is to first draft your cover letter in a Word document or Google Docs, then copy it to the body of an email or the application software.