There usually won't be a USPS postmark date (also known as a time stamp) on a letter sent through LetterStream.com as we use a postal permit, also known as an indicia. More information regarding a postal indicia.
However, our website does provide you with events times for our part of the process (such as when the job was created and when it was paid for). This information lives within your account on the My Jobs page, just left to every job you've created. To see all of the available LetterStream event times for a given job, simply hover over the date and time that's located to the left of the mailing. Additionally, if you sent certified mail through us you can also use the USPS tracking information to provide you with further updates after our part of the process has been completed.