How do I know that ITR has been filed successfully?
If you are filing on the last day, there might be delays as servers are overloaded. So, make sure that you have received an acknowledgement number from the tax department. This acknowledgement is sent on your registered email.
Look for an email from DONOTREPLY@incometaxindiaefiling.gov.in with subject 'Confirmation on Submission of IT Return'. The ITR V is usually attached that states the acknowledgment number. If you do not get this email, it could be that your return was not submitted successfully and you may have to refile. You still have to verify your ITR V. You can verify either electronically or mail the signed ITR V to the processing centre within 120 days of filing the return.