Open rates on marketing e-mail and newsletters dipped in Q4 of 2005, according to the Q4 2005 E-mail Statistics report released by eROI.

From the Q3 to Q4 2005, open rates dropped 29 percent. Click rates fell 21 percent in the same period. The report speculates image blocking in Gmail, Outlook 2003 and other e-mail clients chipped away at open rates. The sheer volume of e-mail received over the holidays is another factor considered by the e-marketing agency.

The study finds Friday to be the best day to send e-mail. The past two quarters show a tendency for higher open and click rates on Friday. Tuesday gets the second-highest open rate, with Thursday earning the second-highest clickthrough rates.

This report confirms the best day in which to send your emails to ensure the best opening rate, the enclosed chart and description explains it all, courtesy of clickz.com