Is your Apple Mac Mail inbox overflowing? Is it difficult to find emails you know you received, but cannot retrieve them? Archive mail in a database that makes backup and search easier.
The amount of email arriving in our inboxes each day can be overwhelming. Dozens of messages demand you deal with them asap and older messages get pushed down the inbox list by new ones. It does not take long for emails to become buried so deep in the inbox that you struggle to find them.
The search feature in Mac Mail is quite good and it is a great help when you need to find an email from weeks, months or even years ago. Click in the search box in Mail and start typing. There are useful suggestions after each letter entered. Type just one letter and it will suggest people, subjects, mailboxes and attachments. Click a suggestion, the search is performed and the results are listed.
Alternative to Mail on the Mac
Mac Mail is OK and the search facility can do a lot, but sometimes search can be confusing, especially when trying to build complex searches. MailSteward is an alternative email search tool that you may find easier to use. It also acts as a backup for your emails and, if you want, you can archive old emails in it to cut down on the bloat in Mac Mail.

There are Lite, standard and Pro versions of MailSteward, each with increasingly higher email limits, 250k for standard and millions for Pro. Any version can be downloaded and used for free for up to 15,000 emails. That is a lot and I have less than this in my email account. However, some people that have been using Mac Mail for years and are very active could have 10 times that number. If your email usage is light, like me, the free version is OK.
Archive emails in Mac Mail
MailSteward works by creating a database in the Documents folder on the Mac. After giving it permission to access the disk and Mail, it copies all emails in all inboxes into the database, including attachments. You can browse email the list of messages and select emails to view them in the usual way and it is like a simple email app.

The database is a single file and contains everything from Mail, so it is therefore a backup. If anything happened to Mail or its contents, you could still access your emails in MailSteward. You can also backup the MailSteward database too, so you should never lose another email through a disk error or corruption.
Now that there is a copy of all messages in MailSteward, you could delete some of the older emails in the Mail app. Do you really need to store emails from years ago that you will probably never need? They are safe in the database and can be cleared from Mail. This might even help Mail if it is getting bogged down with a very large number of emails.
Search for emails
A major benefit of MailSteward is the search feature and it is easier to build complex searches than with Mac Mail. The search form has start and end dates at the top, plus buttons to automatically select 7 days, this month and this year. It is easy to narrow a search to a specific date period.

It is also easier to choose what parts of an email to search and there is a long list of items, like From, To, Subject, Body Text, Attachment type or name, and so on. Each one can be AND, OR, AND NOT or OR NOT, so you can say ‘find emails with this or that and not something else’. You can choose the type of attachments from graphics, documents, sound, video and compressed files by ticking checkboxes.
Tags can be added to emails and these can be searched. Notes can also be associated with emails and these can also be searched. Adding tags and notes to messages can be very useful for remembering what emails were for or about.
A search can be performed on search results, so if you cannot immediately see the message you are looking for, you can search again in the results.
More features
There are Reply and Forward buttons in MailSteward, but it is not an email app and it opens a new compose email window in Mac Mail with the selected message. It can then be sent in Mail. A simple switch between HTML (standard email these days) and plain text source code enables you to see things like where links really point to before you click them, which can be useful for avoiding phishing.

There are useful export options that enable you to save tab or comma delimited text, a list of email addresses and more. Search results can be saved to a file, all attachments can be saved, raw source text can be saved and so on.
Conclusion
MailSteward offers an easy way to backup and archive emails on the Mac. Having a copy of your inbox and sent emails elsewhere is useful in case of problems.
MailSteward makes it simpler to build complex search terms than the Mail app. The search criteria are obvious and easier to select. This means it is easier to find messages that may be buried deep in the inbox.
Notes can be attached to emails, which could be useful for some people and you could store bits of information with a message. The app supports tags too, but Mail does that just as easily.
Not everyone needs MailSteward, but some people could find it very useful. Especially if they have a lot of messages going back years that they often need to find and refer to. For people with less than 15,000 emails, the app is free.