When comparing Postbox vs eM Client, the Slant community recommends Postbox for most people. In the question“What are the best e-mail clients for Windows?” Postbox is ranked 9th while eM Client is ranked 11th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Clear interface
Pro Forgotten attachment reminders by default
Reminding the user that they forgot to attach the file if they mentioned one in the body of the email is one of the most useful features of any email client and so many don't include this. Postbox is pre-configured to look for certain keywords (attached, CV, spreadsheet, pdf etc) and you can specify your own keywords in addition.
Pro Blocks tracking gifs
Has the ability to block tracking gifs commonly used for read receipts.
Pro One Inbox for all accounts
All messages in one place. But you can select to show only messages from each account either.
Pro Quick Bar for macros
Quick bar allows you to add a variety of content to your message. It will let you reuse URLS in your Sent folder, and autocompletes against canned responses, signatures, and topics.
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 No support forum
Support for paid product has no online forums.
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.