QB Issue Resolution:

Are customers claiming they aren’t receiving the invoices or is there another way you know the invoices aren’t being sent out?

From my experience with QBO invoicing I think the best way to solve this issue is to test the email account with QBO.  Create a test customer that has your email account.  Make the test customer email account a gmail account or something different than the email account sending the invoice.  Then send out a test invoice to the test customer and see if you receive the invoice.  If you do receive the invoice, it may be your customer that has the issue.  If you don’t receive the invoice, make the gmail account your company email account and make your MS Exchange account the test customer’s email account.  Send out a test invoice and see if you receive the invoice.  If you do receive the invoice, it’s probably MS Exchange.  If you still don’t receive the invoice it could be something in QBO.  Based on your post I’m guessing it’d have to be related to switching to MS Exchange.  This will only help with diagnosing where to look for the issue but it should get you started.

As a QB ProAdvisor I run into issues like this; more problem solving than accounting related.  I take the approach mentioned above as QB support might say it’s an MS Exchange issue and Microsoft support would probably say it’s a QB issue, which leaves you in the same spot you’re in.   After testing make sure to delete the test invoice and change your company email address.

Resolution for Issue 'QBO not sending emails' available: Yes (Solved).
Source: Intuit Community forum.

QBO not sending emails: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

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