Org-capture template containing a date relative to when an email was received

Question

As the title describes, I want to be able to create an org-capture template which allows me to specify a relative date (say, 2 days) from when an email was received and print it out. The solution below uses the current date and so does not work. The alternative would be to use the available org-capture template %:date-timestamp or similar but that does not allow me to specify a date relative to when it was received (as far as I know). Thank you in advance for any help.

(setq org-capture-templates
      ("c" "Client-email" item (file+headline "~/org/NOTES.org" "Client reply queue")                
       "- [ ] [[mu4e:msgid:%:message-id][%:fromname]] DEADLINE: %(org-insert-time-stamp (org-read-date nil t \"+2d\"))"))

Answer 1

One can use one org-read to read the date from the mail and another one to increment the number of days as you wish. The following replacement of the relevant snippet of code does work for me:

%(org-insert-time-stamp (org-read-date nil t \"++2d\" nil (org-read-date nil t \"%:date\")))