Arno Selvini, head of CRM for Star Stable, a video game product for girls who like horses and an introduction to digital gaming, said Agile works for his six-year-old company with 140 employees.

You can create forms, polls, countdowns, live text, and/or personal images in emails. An example is merging external content with your images, e.g., a weather forecast.

"If you have a general rule in email marketing, if you have a Constitution, the first article is to keep optimizing, keep testing, keep changing. Changes are good."

"It is helpful for getting to know your customers with direct feedback within two minutes of sending out a campaign. You might see something like, 'Whoa, it's not working on this device.'" It's easy to then make changes."

Mic Conetta, head of CRM for Arsenal Football Club, amused the crowd at MediaPost's Email Insider Summit Europe on Wednesday by mimicking now-former Arsenal player Jack Wilshere's monotone.

After one year, the company sent email as part of an integrated marketing approach: apps, website, cross- and upselling gas and convenience products.

"And then we found out the unsubscribe link had disappeared," said one panelist. "Luckily, this was before GDPR, but it was, of course, a disaster."

"We are trying to overlay a bit of common sense and a bit of business knowledge. If you don't recognize [your customers], you aren't going to be talking to them in the right kind of manner."