If the e-mail address of members cannot be changed, this is by default because the desired e-mail address is already in use with a member. You can merge duplicated members as following: Merge duplicate members

If the members can't be merged because there is no double member in the customer base, it is possible that the member has been deleted and is listed under the deleted members. To get to the deleted members, do the following: 

  • Click in the admin area on «My customers».
  • Click «deleted» after the row of letters.
  • Search for the member in the list and click on «Action»
  • Restore member: If there is data or information in the deleted member that is needed, you have the option to restore that member and then merge the two accounts.
  • Delete permanently: If the data of the deleted member is no longer needed, you can delete the member permanently. Afterwards you can change the email address at the member in your customer base as desired.

You can also find more about deleted members here: Delete and restore a member