The logical place to place e-mail responses would be Comments as these are both visible to users and the place for technicians to look for user feedback/interactions.
Additionally, this makes OnCommentAdded ruleset run when an e-mail response comes in, allowing for example informing technicians about user response.
The comment is added from the open SD.Email.Monitor poject. Customizing to change the comment type is quite simple:
Note: Adding a Process Comment will add the same comment to Process History as well, this is normal.
The Comments and Process History web parts are configured slightly differently with the comment body shown in Comments web part being shorter. You may want to edit the SD Incident View page to show more of the comment description. All actions to change the pages need to be done with Administrator user in Portal.
First, please make sure that you back up the current page in case you need to revert the changes:
In case page needs to be restored from backup:
Here are the steps to the necessary changes on the page:
It is possible that this does not make Comment entries larger in the web part, in which case, the web part should be re-added with the same settings. A full set of steps to do that follows:
ServiceDesk 7.5 SP1