Extract lines from file, add to new files

[Rich Shepard]

It's been several years since I've needed to write a python script so I'm
asking for advice to get me started with a brief script to separate names
and email addresses in one file into two separate files: salutation.txt and
emails.txt.

An example of the input file:

Calvin
calvin at example.com

Hobbs
hobbs at some.com

Nancy
nancy at herown.com

Sluggo
sluggo at another.com

Having extracted salutations and addresses I'll write a bash script using
sed and mailx to associate a message file with each name and email address.

I'm unsure where to start given my lack of recent experience.

TIA,

Rich