+1 for postfix.

I may also want to type out someone’s email NOT in an email client, while in terminal, for example in bash shell or in vim.

Is there Google and/or Outlook integration into a terminal (Konsole) I’m not aware of?

Because email clients are not the only place where I enter emails. And not every program supports address book integration.

I might be filling out online forms and enter someone’s email or phone number or any other long string such as full name I can’t remember how to properly spell.

Well you can have 1 letter sequences which is almost what you want. For example have a sequence that consists of single “u” key that composes into “ü” or something similar.

I don’t know if it’s the same in every DE/Distro, but in KDE I’m pretty sure I can both hold the Compose key and type sequences, or press Compose key once and then type a sequence.

But can’t check right now.

Could you please ELI5 what are spill ranges?

Tbh I don’t have an answer and this isn’t what you’re looking for, but have you heard of Compose key? I don’t know what is kmomad, but I’m pretty happy with my custom compose sequences.

Could you please explain how is ricing racist?

I use compose key sequences to save time writing out long email addresses. For example, I have something like this in my ~/.XCompose:

<Multi_key> <b> <o> <s> <at>: "myangryboss@company.com" # Email of my very angry boss

So I can just type Compose (right alt on my system), bos@ and get his email address. Less error prone than typing out emails manually.

I’m probably not the only one to use compose strings as a replacement to a text expander, but I don’t know anyone else who does this.