In our experience, the sweet spot in the case of an outbound sales campaign lies between 5 and 7 emails, with a minimum of 3.
This is the formula that brings us here at Overloop the most success in outbound sales campaigns:
Day 1: Initial email
Day 3: Follow-up 1
Day 6: Follow-up 2
Day 8: Follow-up 3
Day 11: Last follow-up
Why no less than 3?
Emails can be overlooked, maybe the recipient wasn’t in the right mood when they read the email and then forgot about it.
The recipient may need some time to come to a decision and your consistency may help them make a step in your direction. As long as you keep it friendly, with a “no pressure” attitude, you’ll be fine.
Why no more than 7?
Before you ask: yes, people sometimes do respond after the 6th or 7th email.
Persistence is key. It is, however, safe to assume that if your contact hasn’t answered within 7 emails, they’re probably not interested, and your drip campaign should end.
Beyond that point, you just risk being reported as spam.
Note: This doesn't apply if you have particularly long sales cycles. But you need to provide value in every email and stay relevant.
Pro-tip: let them know in the subject line that it’s your last email, it might prompt an unexpected twist!
But don’t throw those contacts away just yet. Have them contacted by someone else within the company or add them to a new campaign after 6-8 months.
Obviously, lots of other entities compete for their attention, and unless they specifically asked you not to contact them, they won’t mind if you try to get in touch after some time. You must, however, check that, by that time, your contact is still qualified.