66% of marketers say e-mail marketing offers a “good” or “excellent” return on investment, second only to search engine optimization, which 75% rate as “good” or “excellent” in ROI, according to a new report from Econsultancy.com Ltd. and e-mail service provider Adestra.

The report is based on a survey conducted in January and February of 1,329 marketers spanning in-house teams, e-mail service providers and digital marketing agencies.

Despite the bullish sentiment on e-mail’s value, when respondents were asked to rate their own companies’ e-mail campaigns only 39% rated the performance of those campaigns as “excellent” or “good,” while 15% said they were “poor,” 4% “excellent” and the rest, 42%, “average.”

Design and content eat up too much of marketers’ time, the report suggests. For instance, 18% of respondents spend more than eight hours on developing content and crafting a design for a single e-mail campaign. That time could be better spent elsewhere, the report says.

Respondents said that maintaining clean and up-to-date e-mail lists have the biggest impact on e-mails reaching their recipients (58% of those polled chose this), followed by relevance of e-mail to recipients (45%) and the sender’s reputation (44%). Limiting e-mail frequency was selected by 30% and relationships with ISPs came in last with 8%. Respondents could select up to three answers. (ISP stands for Internet Service Provider and is e-mail provider shorthand for the companies that host consumers’ e-mail inboxes—and at one time in some cases provided their Internet service. These include Yahoo Inc., AOL Inc., Microsoft Corp. and Google Inc.)

 43% of those polled say they use an application service provider or a service hosted by an e-mail service provider for their campaigns, 26% an in-house system (including vendor software they have installed on their systems) and 20% a mixture of the two. Another 6% use an e-mail service provider that both develops and sends their e-mail campaigns. 5% use none of those options.

70% of those polled were part of an in-house e-mail marketing team while 30% worked for e-mail service providers, a digital agency or as consultants.