Has anybody received such email?
How about 15,000+ of them hitting my mail servers today.
Seems to be a rather large run going on at the moment.
Be suspicious of anything sent as an attachment these days.
Companies tend not to send things as attachments unless they have explicitily contacted you beforehand to say such a thing is on the way.
Legit companies will address you by your full name within the body of the email, and usually some obfuscated part of your account number.
If there is no uniquely identifiable information within the BODY of the email, other than your email address (which has been harvested more than likely), then again, the chances are the email is spam.
With regards to the latest Royal Mail malware going round, so far today I've seen at least 40 variants of the same virus. Not all antivirus applications will pick up the attachment as a virus because they simply can't keep up. These days, viruses/malware can mutate multiple times per hour if not minute. (Which is why most good antimalware/virus applications now have 4 hourly updates AND employ real-time cloud based queries).
If ever in doubt and you are actually waiting for an attachment, you can use VirusTotal (at https://www.virustotal.com/)
Here you can upload the suspect file (making sure NOT to double click or open it). VirusTotal will check the file against multiple vendors and give you a good indication as to whether something is safe. But again, to stress, even a 0% hit on VirusTotal isn't a concrete indication that a file is completely safe. You may be the unlucky one to receive the brand new version of a virus.
Hence - trust nothing.