Using the iATS payment extension, credit cards and ACH transactions are going through just like they're supposed to. The only hiccup is that one-time ACH transactions are generating a second 'online' receipt when the transaction is later moved from Pending to Completed via the iATS Payments Verification scheduled job. Is that supposed to happen? If not, any ideas on how to track down what is causing it?
Further Details
When the ACH transaction is first submitted (upon the donor hitting the Submit button on the contribution page), a receipt is issued with all relevant details and the contribution is marked as Pending in CiviCRM (as it should). Later that day or the next business day, iATS receives the okay from the donor's bank and marks the transaction as OK:BankAccept in their system (as it should). When the iATS Payments Verification scheduled job next runs (it runs hourly), the contribution is changed to Completed in CiviCRM (as it should) and a second receipt is generated (??). The second receipt has the basic information (amount, date of transaction, transaction id) and our profile we include in the Online Receipt message template, but none of the financial information nor the billing address info.
The receipt time and date for the contribution is updated to the time of the second receipt and matches when the iATS Payment Verification job ran, so it would appear that is the link. There are two activities in the contact's record, one for the actual contribution when it first occurred and then a second activity for when the contribution status got changed from Pending to Completed.
What causes the online receipt message to fire? Could the recording of the second activity be causing the 2nd receipt?
Civi 4.6.14 (will be updating to 4.6.20 before go-live); Drupal 7.44; iATS Payments extension 1.5.3