Sending Large Attachment Very Slow

A few times a week, I send an email message to two recipients, and the email has a single large PDF file attached. This file is about 5 or 6 MB. Sending this message often takes anywhere from 10 minutes to half an hour. During this time, the rest of eM Client is unusable, nor is there any way to cancel the message.

Bandwidth is not a problem, as I have a fiber-optic connection at home (Verizon FiOS, 80 MBPS upload and download speed). The recipients are a Yahoo web-mail account and a Verizon account.

I am using eM Client version 6.0.21372.0, as a POP client, under Windows Vista Home Premium SP2 32-Bit.

Using Sysinternal’s Process Explorer during this time shows that MailClient.exe is not performing any I/O Reads or I/O Writes, but the number of Page Faults increase by about 70 every second. There is no change in the CPU Time for MailClient.exe while this is happening.

I have 3 GB of RAM on this system; about 900 MB is constantly available during this activity. I have a 2 TB hard drive, most of which is unused.

The rest of the PC functions normally while this activity is on-going.

The last time this happened – this morning – I killed the MailClient.exe process using Process Explorer. I restarted eM Client, and after a minute or two, it seemed to be hung up during it’s checking-for-database-corruption process (the animation was no longer moving). I canceled that activity, and eM Client seems to have loaded properly.

Additionally, checking my Sent folder shows that the mail with large attachment is listed as being sent. I don’t know whether the recipients have actually received it. If they have, it looks as if eM Client does properly realize when it has finished sending an email with a large attachment; perhaps it is not checking something properly.

If the long duration of sending a large attachment can’t be shortened, perhaps this type of activity could be split off as an asynchronous process, such that the rest of eM Client can still be used during this time (to read in-box mail, for instance).


Hi, can you please try to update your eM Client to this release and check if the issue persists? If it does, please download this utility and run the utility when the application is hanging or when it freezes.

The utility will create a dump file in your documents folder, can you please send me the file to with a reference link to this forum topic?

Thank you,

Will do, and I’ll get back to you.

Interestingly, yesterday I sent a 4+ MB PDF attachment to the same two recipients, and it was the fastest ever – took just a second or two.

Just downloaded, installed, and used the newer version (6.0.21899.0) to resend the 6 MB attachment that I had trouble with on Friday. It was sent in just a second or two, also.

Thank you for your help. I’ll be doing this again in three or four days, with a new attachment, and will let you know if I encounter the problem again.

Hi again, glad it works, please make sure to let us know if you come across any other issues or questions about the application.

Thank you,