My campaigns have usually done fairly well in terms of open and click rates, but my last few have really taken a nose dive e.g. open rate dropped from 34% to 2%, and click rates between 0-4%. I've not changed the email address I'm sending from, I use a fairly similar subject line each time, always the same send-from name, and I'm usually 'copying' a previous campaign and editing it, so they really aren't changing much. My email is authenticated. I'm really not sure what else to try! I'm concerned about event ticket sales.
Thank you for reaching out to the Community about your emails! I have taken a look at your account and can see the difference in engagement you mention. In cases where your contacts are not receiving your emails, enabling authentication is a great step. Doing this helps Internet Service Providers (ISPs) identify your email as being legitimate and not from a scammer, spoofer, or phisher. So thanks for turning on that setting. You also mentioned you have not made many changes to your emails over time. Even though this may be the case, I would still suggest sending one or some of these contacts a blank test with an alerted subject line. Sending an email like this allows us to see if they are able to receive any email from our system. You can also have them take a further step of whitelisting Constant Contact in their security settings.
With that said, I have taken a look at your most recent campaigns and can’t see anything that jumps out as a cause. The test email I have to myself also did land in my inbox. Because of this I would suggest calling into our Deliverability Specialists directly for further assistance. These support agents can help look further into these contacts or any campaigns you may be sending in your account.