It is vitally important that email marketers remove invalid email addresses to limit their bounce percentages, an expert has commented.

Ross Kramer, chief executive officer of marketing software agency Listrak, warned that many ISPs have begun to penalize senders with excessive bounces.

"It is imperative for email marketers to keep their bounce percentages as low as possible so ISPs do not block or filter the messages," he urged.

Mr Kramer made his comments following Listrak’s announcement that it has changed the way its system deals with invalid email addresses.

The company’s system now automatically removes such addresses, which it claims will help it to ensure its clients’ messages reach all of their subscribing active inboxes.

Earlier this month, Listrack spokeswoman Megan Ouellet discussed how to keep subscribers reading emails, through a post on the company’s blog.

She reported that subscriber feedback shows it is not usually the frequency of marketing emails which causes people to unsubscribe or to complain.

Firms sending customers relevant and dynamic content will find their emails are valued and read, Ms Ouellet suggested.

Katherine Griwert is Brafton's Marketing Director. She's practiced content marketing, SEO and social marketing for over five years, and her enthusiasm for new media has even deeper roots. Katherine holds a degree in American Studies from Boston College, and her writing is featured in a number of web publications.