Can the date change on jpg attachments when they are downloaded from yahoo email?
No they cannot. The data/timestamp on the image is from when you yourself received/downloaded them. There is no way to manually change the reception date unless you re-download them at a different time.
Google mail lets you add attachments from the same screen where you are composing an email, while Yahoo moves to another page for attachments. Google Mail automatically stores all email addresses to which you sent and receive emails to your contact list. In Yahoo Mail you can opt to save a contact to your list or not.
It is not possible to change Yahoo ID or primary email address. Instead of changing yahoo id you can try below options 1. Create an extra email address - a second email address available with your existing Yahoo account. 2. Create an alias - an extension of your Yahoo account that hides your primary ID. 3. Create a new Yahoo account.