Microsoft had been using very stick spam filtering algorithm for their mail servers over the last 4 to 5 years.  This move has affected many third parties email services and individual from the freedom of electronic communication.
On the other hand, Google through gmail has been improving their algorithm for spam filtering making it sophisticated, effective and user friendly. Instead of blocking the spam like MS do, gmail allow the spam but with a red bar notifying you that, the email is probably the spam with reason
Gmail Suspicious Dangerous Email with reasons

Gmail Suspicious Dangerous Email with reasons

If the email is suspiciously a spam, gmail will also notify you using a yellow bar with reason why that email is suspected a spam?
Gmail Suspicious Email Spam with reasons

Gmail Suspicious Email Spam with reasons

Comparison Between MS Email and Gmail

Google algorithm over spam management is right? Why?

Most of 20-40 percent of suspected spams are not actually spam and it turn that some of those suspected spam email are emails for new job offering, new sales offering, new clients etc

Let take an example

Few years ago, a friend of mine who a Kenyan by origin was checking email using his gmail account and after finishing reading the mauls in the inbox he decided to delete all mails in the spam folder but in the first and second attempts he hesitated and in the third think-out, he decided to go through the headings of the spam folder emails and surprisingly, he discover one email in the spam folder titled “UN JOB OFFERING”

When opened the email message, he just found that he got a job with UN in IT related job in Pretoria, South Africa for the interview carried out online some two to three weeks before.  If that friend of mine was he using Microsoft email, I guess that job could just expired without his knowledge.

MS Emails

Gmail

Microsoft server block all suspected spam and give you no choice to decide weather is true or notGoogle server let all suspected spam to your spam folder and give you the choice to decide weather is true or not
Microsoft server block all suspected spam and never warn you or give details about the suspected spamGoogle server let decide to block manually, delete or change to non spam if accidentally tagged as spam by the system. Google also warn you and give details why that email is the spam according to Google
Microsoft claim they detect 97% of spam

??? most of the blocked emails are from genuine IP addresses

Google claim they detect 99% of spam

I highly agree with this claim

How many opportunities had, have or are going to expire without your knowledge because of this aggressive algorithm used by Microsoft to block out some genuine emails from third parties?
For those who are not aware, Microsoft since last four years or so if I am not mistaken implemented a very strict spam filtering policy which affect new IP addresses. If you are using email hosted in the new IP address, then you are the Victim of this. Your email will be suddenly blocked if you send to any recipient with Microsoft related email like those end with live.com, hotmail.com, outlook.com etc
Sample of mail delivery failed from Microsoft after blockage

Sample of mail delivery failed from Microsoft after blockage

From out opinions we advice our customers and others to avoid using Microsoft emails alternative you can trust and use gmails for quite many reason one of them mentioned above and the other one are: they provide enough disk space, secured interface, robust email management thread like nature and many other applications and services.
If you do not believe me, you can follow  the link below and read the thread about how people are complaining about the problems since 2013 to date and no remarkable action taken by Microsoft to correct the problems