Marketers hoping to break through mailbox clutter and reach potential consumers with promotional emails most often use the words “news,” “party” and “free,” in their subject lines to entice readers to open their messages, according to a report from MailerMailer.

An analysis in MailerMailer’s ninth bi-annual Email Marketing Metrics Report, revealed the top 10 most popular words in email subject lines:

The report, which provides an analysis of trends in email marketing across industries also found that religious and spiritually themed emails get the highest open and click rates compared with other industries:

Telecommunications, transportation/travel and banking/finance also attracted more attention than others from an  aggregate industry perspective, MailerMailer said.

Additional findings from the report:

• Emails are being opened sooner: 32.6% of all opens occur within the first two hours compared with 29.57% six months prior.
• Click rates have held steady since last year, rising just slightly by 0.08% in the second half of 2008.
• Email deliverability continues to increase as evidenced by the fact that more emails are reaching recipients’ inboxes.
• Emails have the highest open and click rates at the beginning of the week, particularly on Mondays.

The report also provides instructional material for designing mobile-friendly emails in response to the growing trend toward viewing email on Blackberrys, iPhones and other hand-held devices. This behavior, MailerMailer said, is increasing the need for marketers to pay attention to this segment of their target audience.

About the report: MailerMailer’s report covers the performance data of more than 300 million emails from 21 different industries from July to December 2008. Report readers can view and obtain a copy of a word cloud depicting the popularity of these words to use on their own blog or website. Both the publication and the word cloud can be downloaded here for free.