When comparing GyazMail vs eM Client, the Slant community recommends GyazMail for most people. In the question“What are the best e-mail clients for macOS?” GyazMail is ranked 6th while eM Client is ranked 13th. The most important reason people chose GyazMail is:
Goichi Hirakawa, the main developer of GyazMail, has been committed to his project since 2003 and delivers updates regularly.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Long term support and development
Goichi Hirakawa, the main developer of GyazMail, has been committed to his project since 2003 and delivers updates regularly.
Pro Mail sorting rules
The user can define complex mail sorting rules for incoming and outgoing mail.
Pro 64-bit support
As of v1.6
Pro Native Cocoa API based
GyazMail is a native macOS application, based on the Cocoa API.
Pro customizable fonts & colors
the mailbox view is very comfortable
Pro Very good support for Asian languages
GyazMail is a Japanese product, so it has very good support for Asian languages.
Pro Supports older versions of macOS
GyazMail is available for all versions of Mac OS X / macOS starting with version 10.1
Pro Freely selectable hard line wrap
In GyazMail you can set a maximum number of characters per line. The program will wrap the lines using hard wrapping on sending. This feature is very useful for newsgroups that require a hard break after 72 characters.
Pro Supports a big variety of character encodings
Uses Oniguruma regular expression library, which is a very elaborate regular expression engine that supports a big variety of character encodings. This makes very much sense with e-mail, as in an e-mail theoretically any character encoding could be used. Because it is free software (BSD), written in C, very elaborate, stable and still actively maintained it is also used in Atom, Take Command Console, Tera Term, TextMate, Sublime Text, SubEthaEdit, and jq.
Pro Many useful options
Such as sorting through categories, etc.
Pro Free and paid version
It is free for 2 accounts and as long as you don't use it commercially. Paid version comes with support and can handle more than 2 accounts.
Pro Still actively developed
They've been developing and improving it consistently for years.
Pro Calendar inclusive
Pro Beautiful interface, customisable to your needs
Pro It's simple to add new accounts
Pro Includes Quick Text
eM Client seamlessly integrated the Quick Text extension that was available on Thunderbird. This makes it easy to quickly auto-insert dynamic text, based on many variables, saving time and the need to tediously repeat manual text replies.
Pro Chat included
eM Client includes integrated chat, so you don't need another application for chatting with your friends. All common chat services supported (Google chat, Jabber and others).
Pro The only email client which synchronizes Gmail contacts properly
Pro Doesn't replace your attachments with "winmail.dat" files
eM Client sends straight .pdf files for fax messages flawlessly.
Pro It doesn't store all emails on the disc
It saves space, unlike Thunderbird.
Pro It is still the best in this class
But only because it has no alternative.
Pro A perfect companion to your Gmail or other webmail you might have
It provides (almost) complete Gmail functionality (calendar, tasks, chat, contacts), while offering advantages of an application: offline use, more e-mail providers in one place, very good design, support, etc.
Pro Very fast
Cons
Con Looks old and outdated
Con If connection drops or times out, Gyazmail just sits there until you click OK button
Con Cannot remove attachments to save space
Con Still a 32-Bit app
Con Extremely slow opening emails
Con Some syncing errors with Hotmail
Happens from time to time.
Con Bloated
Huge size, high memory consumption, uses CEF (Chromium Embedded Framework).
Con Lifetime Upgrades are expensive
Con Account options are not shown under right click
Con Terrrible in handing unread emails
Sorting of unread emails is very useless when compared to other email clients.
Con Poor integration with Yahoo Mail
Integrations with a Yahoo Mail account doesn't always work well in eM Client.
Con Not many options to manage IMAP folders
For example, all emails from Gmail will unnecessary synchronize.
Con Interface is too simple
Many options are too hidden and it takes at least 3 clicks to set them up.
Con No conditional formatting
Con Only has one nice interface/skin
The other available skins has a 90s feel to them.