Since email clients place a restriction on the number of characters allowed for both the From line and the Subject line, you may experience instances of being cut off when the limit has been reached. Each email client differs in the number of characters they allow. Benchmark Email recommends keeping it below fifty to help ensure your Subject and From lines are not cut off.

Use those fifty characters to create an enticing Subject line that will encourage your subscribers to open your email. Also, use a From address that people will recognize to boost open rates.