Someone sent me an email saying that Walmart had a $50 gift card for me. The sender on the email is listed as "surprisenetworks.com. It may have a foreign source ("surprise"?). Are there other safeguard places I should contact? I have no dealings with Walmart.

Those online gift cards are just scams and there is NO records. Delete each and every one of them without opening the email.

In general, if the sender's email does not come from the domain of the purported gifting company, it is a scam. Also in general, if it sounds to good to be true, it probably is a scam.

impossible to say with the information given, however, it is not possible to 'hack' a phone number, spoof it yes. That means phoning people with what looks like your number as the sender. This tactic is used my marketers cold calling people to sell online pharmacy drugs and those 'congratulations you have won a cruise' phone calls. Sometimes you will get a phone call from someone saying that you called them, when you didn't.

email hacking is a whole different subject and if your email is being used by someone else, the first thing they do is change the password so you can't get in. In such cases, it hasn't actually been hacked, you gave them the details by tricking you. Once again it is possible to spoof your email address as the sender, and at the moment I am getting emails that appear to be sent by me, to me, offering erectile dysfunction drugs online.

Contact Amazon directly-
Amazon com Help

How do you know it was not delivered - i.e., did the sender receive a return email notice that it was undeliverable or did the recipient receive anything at all? If it was sent and just disappeared, there may have been a problem with the email address. If an "undeliverable" notice was returned to the sender, there may have been a problem with the recipient's server, email program or virus software.

Outlook has several settings which prevent certain types of emails from being delivered or received. It attempts to block anything that looks like spam. For example, emails with too many attachments, certain types of extensions, large picture files, emails being sent out to too many people at a time, etc. Some of these setting can be changed, but some cannot. You don't say which version of Outlook you are using. If it has not worked when you are sending the card directly from the Hallmark program using Outlook as your default email program, you might try opening Outlook and creating an email from there and attaching the card.

The source of the problem could also be the virus software of the sender or the receiver.

On a computer, simply go to Facebook.com, then choose to change your password in the upper right hand corner of the screen. The following link from Facebook explains more:
Help Center

Change your password on Facebook and then restrict walmart's access on your account.
Go into settings and block them.

If it is an email you are sure that doesn't contain any viruses and you know for sure who is the sender (that is not someone pretending to be that sender), then you can add the address to your contact list. All the future emails from that address will open normally.

The gift card can be register at whatever website it is from.
Ex. Target Gift Card = target.com
Ex. Walmart Gift Card = walmart.com
Ex. Amazon Gift Card = amazon.com

It "could" be spam email. If you are sure it's not mail you would want to receive from that sender, in Outlook you can right-click the message and add the sender to the "Blocked Senders List." Further, you can create a rule to handle email from this sender.