When running Nylas Mail with --background (or -b) it doesn't start in the background, instead it starts the first startup screen.
Author: hacker1024Created Apr 24, 2017Updated Oct 30, 2021
Are there any related issues?
#1251 Kind of related
What operating system are you using?
Linux Mint 18.1 (64-bit)
What version of Nylas Mail are you using?
2.0.18
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Bug?
Do you have any third-party plugins installed? If so, which ones?
No
Is the issue related to a specific email provider (Gmail, Exchange, etc.)?
No
Is the issue reproducible with a particular attachment, message, signature, etc?
Try running /path/to/nylas-mail ---background or /path/to/nylas-mail -b
Screenshots

Feature Request?
Does this feature exist in another mail client or tool you use?
...
Source: nylas/nylas-mail