Outlook sends Mail very slow to Office365

Hi Andre,

Outlook performance is just like any other application. It relies on CPU, Disk, Network and other conditions. If any of those resources are performing badly, then the end customer is likely to experience a poor performance. To narrow down the cause, I’d like to confirm some information below:

1. Do all emails sent out slowly in the Outlook client?

2. Your Outlook version such as Outlook 2016 (16.0.6001.1043). Make sure your Outlook is up-to-date.

3. Are all users in this network environment experience the poor performance when using Outlook client?

4. Have you run the Office 365 Client Performance Analyzer tool? Please provide the entire result after running it with us for troubleshooting. To run the tool:

https://support.office.com/en-us/article/Office-365-Client-Performance-Analyzer-e16b0928-bd38-423b-bd4e-b8402bc106aa

To protect your privacy, I have sent you a private message to collect the result after running the tool. You can click the URL below to read and reply to it:

https://community.office365.com/en-us/user/conversations

Regards,
Larry

Hi Larry,

we did all the test, one of your collegues had analyzed the logfiles and found no issues. He told me, to post the questions in this group.

All the clients in the network have the same problem sending bigger mails in Outlook. With small mails the problem is not significant, because the speed of 50KByte/sec is sufficient. But sending big mails is a bad experience, because the users are waiting and waiting.

All uploads to the cloud are fine, only sending mails with Outlook to the MS datacenter is the problem.

I send you the result in the private message.

Thanks for your help!

Regards,

André

Hi Andre,

Thanks for your reply.

We will check the log with related team. To narrow down the issue, could you please provide the following information?

1. What’s the detailed version of your Outlook clients? We can do some tests based on your information.
2. Can you try the Outlook in the clean boot computer? You can also disable the add-ins following the steps given below:
·         In Outlook, click on File< Options< Add-ins.
·         Under Manage select COM Add-ins.
·         Click on GO options beside Manage, uncheck all the add-ins and click Ok.
·         Try to open Outlook and check if it works fine.

Best Regards,
Erick

We tried all these steps a few weeks ago with no success. It is a fresh install of Outlook 2016 from the Office 365 portal.

We think, that Outlook uses a download connection, where the bonding between DSL and LTE in the router is not switched on. We are looking for the reason of this behavior.

Any ideas?

Regards,

André

Hi Andre,

As we discussed in your last post, this upload speed slow issue could be related to Outlook client side settings and Office 365 datacenter. In this case, we will need to further consult relevant team for more information. Thanks for your time and understanding.

Regards,
Yang

Which Team shoud I consult? What is the next step?

Regards

André

Hi Andre,

I notice that you said this in your previous thread:

“We imported mails from a pst-file and we saw an upload Speed round about 70KBbyte per second. And the same speed occured, when we are sending mails with 5 or 10 Mbyte.”

After doing some consulting, I find ‘70KB per second (4.2M per minute)’ when uploading PST files or sending emails is a normal speed. And from the logs you provided, the speed is fine. So it’s an expected behavior that it will be slower than usual when sending large emails. Your understanding is appreciated.

Regards,
Larry

Hi Andre,

I have reviewed the whole thread. I can fully understand Outlook client encounters slow performance issue when sending emails. From previous troubleshooting, this should be a client issue.

Our Office 365 forum mainly focuses on Office 365 for Business online service. Which email account have you configured in Outlook client, Exchange Online account or other email account.

1. If it is an Exchange Online account, I’d like to escalate the issue to our escalation team for further investigation. To escalate the issue, we need to collect your Office 365 tenant information, and contact your Office 365 administrator. Are you the administrator? If not, please involve your Office 365 administrator into this issue.
To protect your privacy, I have sent a private message to request the tenant information. Please use this link to access the private message: https://community.office365.com/user/conversations

2. If it is not an Exchange Online account, to provide you with a better service, I suggest you post at Outlook client forum below:

https://social.technet.microsoft.com/Forums/en-US/home?forum=outlook&filter=alltypes&sort=lastpostdesc

They are more proficient at Outlook client configurations.

Thanks,

Neo

Hi Andre,

If you’re using Exchange Online account, please provide the tenant information for further troubleshooting.

Thanks,
Claud