Q: Unsubscribe not happening

Hi maureenfrommandurah,

Welcome to the Apple Support Communities! I'm sorry to hear you are having these issues with mail on your iPad. While there is no direct way to block an email sender from your iPad, there are ways to reduce the overhead in dealing with unwanted messages. If you continue to receive unwanted messages, you can mark them as Junk as outlined below (this works most directly with iCloud accounts, but should work with other email providers as well):

If you think a message may be junk mail, don't open it

Sometimes the seemingly innocent act of opening a questionable email can alert spammers that their message was received and opened at an active email account. This can encourage more junk mail. To avoid this, you can delete any messages that look like junk mail before you view them.

You can also use the Mail app to mark messages as junk so that later messages from the same sender are automatically marked as junk:

• In iOS 7 or later, open the message, tap the flag icon at the bottom, then tap “Move to Junk”.
• In OS X, select the message and click the Junk (thumbs down) icon in the Mail toolbar.
• At iCloud.com, select the message, then click the flag icon and choose “Move to Junk”. Or just drag the message to the Junk folder in the sidebar.

iCloud: Identifying and filtering junk mail - Apple Support

Your email provider may also offer more direct server-side blocking or filtering options. For example, iCloud allows you to set up filtering that occurs before the mail even reaches your device:

iCloud: Filter email automatically

Regards