Email Marketing & Publishing October 2004

Best Practices
When to send
By Randall Litchfield

Most email marketers have an anecdote or two to share regarding the best day and time to mail. The traditional test has been open rates, which suggest when people are most receptive to reading your message. More recently - with as much as 20% of all legitimate email failing to reach the Inbox - deliverability has become a factor and this seems to be influenced by the time a message is sent as well. Why? Spam filters now consider time and day as part of their spam identification process.

We can thank Return Path for this insight. Their latest Deliverability Index covers 16,000 campaigns and 3.4 million email messages. The findings not only reveal the best days to send mail, but also the best times of day. And the swings in results are significant - deliverability can vary by a as much as 10% depending on when you send.

Here are some of the main findings:

Best Day of the Week: No doubt about it - it's Monday. Overall Monday mailings enjoy 1% higher delivery rates than average, and nearly 3% higher than the worst day to mail, which is...

Worst Day of the Week: Saturday, with Sunday a close second.

Best Time of Day: The highest delivery rates were obtained on mailings sent between 6 - 10 a.m. ET. Deliverability rises 2% above average, and 5% above the worst time, which is...

Worst Time of Day: 10 a.m. - 2 p.m. ET. No mystery here - according to recent data reported by SpamCop, most spam is reported between 9 a.m. - 3 p.m.

Worst Day/Time Combination: Saturday or Sunday from 10 a.m. - 2 p.m. Suicidal. Deliverability will drop a good 10%.

Bottom line: Week days are better than week ends; early morning is better than late morning or afternoon.