Re: [PATCH v3] Allow applying filters to summary consecutively

[Gregory Heytings <gregory@heytings.org>]

>> As you probably know, Maildirs were proposed about 25 years ago to 
>> address the limitations of mbox files,
>
> I don't consider mbox files limited.  Why do you think so?
>

My opinions are not important, facts are.  The fact is that:

1. Mbox files do not scale.  It is not uncommon to have mail folders that 
are several Gb large, and opening a 50 Kb email in say a 2 Gb folder means 
reading the whole 2 Gb file.

2. Mbox files are fragile.  If for whatever reason a program crashes while 
updating an mbox file, the whole mbox file can be corrupted, or even lost.

3. Mbox files are slow.  For example, when an email in the middle of a 
mail folder is deleted, or moved to another mail folder, the whole mbox 
file must be written again.

4. Mbox files cannot be accessed concurrently by two programs, e.g. the 
mail delivery agent and the mail user agent, or two mail user agents.  In 
practice most people access their mail with several mail user agents, e.g. 
on laptop computer, a desktop computer, a tablet and/or a mobile phone. 
Another common pattern is two or more people using a shared mail folder, 
e.g. for the "contact" email address of a company.