A SQL Server technology that supports the creation, management, and delivery of both traditional, paper-oriented reports and interactive, web-based reports.
"My Subscriptions" only shows ones you created. Yours were set up by someone else (an admin).
In the web portal, open the report then menu then Manage then Subscriptions. This lists all subscriptions on it. With Content Manager rights you can edit them regardless of owner.
Can't find them? In Query ReportServer DB:
SELECT c.Name, s.Description, u.UserName AS Owner
FROM Subscriptions s
JOIN [Catalog] c ON s.Report_OID = c.ItemID
JOIN Users u ON s.OwnerID = u.UserID
WHERE s.ExtensionSettings LIKE '%your.email@domain%';
Edit/delete there, or have the owner/admin do it if you lack rights.
If they're data-driven subscriptions, recipients come from a query, change the source data, not the subscription.