“E-mail recipients probably aren't going to buy something from another company on their BlackBerry or iPhone, but they certainly might flag something or take action on it later back at the office,” said Janine Popick, CEO of VerticalResponse Inc., a San Francisco-based e-mail marketing service provider.

Many smart phones aren't user-friendly when it comes to reading large chunks of text or viewing big images, so marketers must tweak their messages to appeal to b-to-b subscribers scanning their e-mail initially from a mobile device, she said. Popick suggested the following tips to maximize the punch of e-mails—whether they're read at the desk or on the go:

• Survey your subscribers first. Try to determine what percentage of e-mail recipients is reading your messages initially from their smart phones, Popick said. One way to do that is to add another question during the opt-in survey. If a high percentage of registrants affirms they are using their iPhones often to read your e-mails, you might consider rethinking your overall campaign to makeit more amenable to handheld devices, she said.

• Keep subject lines compelling and concise. Because some recipients may see only a subject line—and not any of the text of the e-mail—on their phone, marketers need to craft a great phrase there to grab the attention of all recipients, Popick said. “It should be short, sweet and to the point,” she noted. Also, she said, avoid using the “from” label in your subject line to save space.

• Place critical information at the top of the e-mail. Because some mobile phones do show a few lines of text right away, try to convey the most important pieces of information in the first lines of the text, Popick said. Besides, she said, “people hate scrolling on their phones, so you want to avoid that by making your message as concise as possible.

• Include a text version with an HTML and call link, too. Many older mobile devices can't show HTML versions of an e-mail, so it's a good idea to include a text version of your message as well, Popick said. The default setting on the phone will recognize which version to show its user.

In addition, many smart phone users don't like to download the rest of e-mail messages when prompted. For that reason, marketers should keep their messages very short and include a “call” link to connect recipients directly to the company if recipients want more information right away, Popick said.

• Consider using your logo. Popick is a fan of placing logos near the top of an e-mail for branding reasons, even though some mobile devices don't render images as well as others. “Mission and branding is really big for b-to-b marketers,” she said. Placing your logo in the e-mail probably won't hurt you—even if the image doesn't render properly, she said. “Just make sure your image isn't everything you're showing at the top.”