It is possible that you are not successfully receiving lead notification emails from your lead sources (e.g., website or lead gen provider) but Speak2Leads is.
Here are some troubleshooting steps you can take:
1) Contact your lead gen provider and verify that your correct email address is listed as a recipient on the distribution list set up to receive your leads.
2) Contact your web developer to verify your website form and landing page forms are working properly, and your correct email address is listed as a recipient on the distribution list to receive your leads.
If you are posting leads from your sources directly to your CRM system, follow the steps above and verify that the posting for each source is set up properly.