Check if email was send inside a capmaign

Hi guys,
Just checking if it’s possible to do something that might be a bit complex.

So i have a campaign that send 1 email every 2 days for about 2 months.
I have also set the email type as marketing but that doesn’t do what i want.

Let say a user left the subscribe list and than joined it again.

I want the user to start from where he stopped getting mails but when the email type is marketing that mean i have to wait 2 for each mail just to find out the mail was already sent.

The problem is that if the user got 5 mails and the capmaign started again he will have to wait 2 days for each mail untill he will start getting mails again (which mean in total about 12 days for the next mail - the 6 mail).

Is there a way for me to check if the user got the mail before i make him wait 2 days?
The idea is to pass the 5 mails and go into mail number 6 without waiting 12 days but only 2.

If that is not possible which is probably issent let try and check different option.

Is there a way for me to save so kind of array with data after each mail is sent and than check on each mail if it contain the data before sending?

If i am not able to save an array is there a way to save only text that keep updating?

So the idea is to save the mail id number on a custom field value (in some kind of array) and than check if the “Form field value” contain the mail id and if it does i will move on to the next mail.

So for example after the first mail i will save the data of the email id which is 7, and on the second i want to add to 7, the number of the new mail which is 8, and than i get 7,8,

Than before i send the first mail i will check if the field value have the text 7, and if it does i will move on to the next mail and so on…

I know it complex but it allow me to restart campaigns and i hope what i wrote make sense.

If anyone has any idea on how to do what i am after i will be happy to hear about it.