Cannot view emails unless connected to the internet

I constantly receive email newsletters from various sources but some of these I cannot view unless I am connected the internet.  Why is that so?  The emails comprises of both text and pictures but, if I am not connected to the internet, nothing appears - just blank spaces.  Is there any way to correct this so that the emails can be viewed even if I am not connected to the internet.

If the pictures are actually links to pictures on web sites then you need an internet connection to see them.

Several email clients (outlook being one of them) can be set up to not download or open pictures until you request it.  I think this is because so many people are reading their email on smart phones and don't want to use the data that the pictures take.  But for whatever the reason, without additional information, I see no reason to believe it's a virus.