What is Ymmapi.dll?

Ymmapi.dll is a Windows DLL file. DLL is the abbreviation for Dynamic Link Library. DLL files are needed by programs or web browser extensions, because they contain program code, data, and resources. You can fix your Ymmapi.dll problem by downloading the correct Ymmapi.dll file. The following information can help you determine if Ymmapi.dll is a Windows system file or if it belongs to an application that you can trust.

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Ymmapi.dll file information

The process known as YMMAPI Module or Yahoo! Mail

belongs to software Yahoo! Toolbar or YMMAPI Module or BT Yahoo! Applications or Yahoo! Browser Services or AT&T Yahoo! Applications or Yahoo! Mail or Toolbar or SBC Yahoo! Applications or Verizon Yahoo! Applications

by Yahoo! (

Description: Ymmapi.dll is not essential for Windows and will often cause problems. The Ymmapi.dll file is located in a subfolder of "C:\Program Files" (mostly C:\Program Files\YAHOO!\COMMON\). Known file sizes on Windows 10/8/7/XP are 285,464 bytes (40% of all occurrences), 190,496 bytes and 5 more variants. 
A .dll file (Dynamic Link Library) is a special type of Windows program containing functions that other programs can call. This .dll file can be injected to all running processes and can change or manipulate their behavior. The program is not visible. There is no detailed description of this service. It can change the behavior of other programs or manipulate other programs. Ymmapi.dll is not a Windows core file. Ymmapi.dll is a Verisign signed file. It is digitally signed. Therefore the technical security rating is 48% dangerous, however you should also read the user reviews.

Uninstalling this variant: If you want to remove the program completely, go to Control Panel ⇒ Software ⇒ Yahoo! Toolbar or Yahoo! Browser Services.

Recommended: Identify Ymmapi.dll related errors

If Ymmapi.dll is located in a subfolder of C:\Windows, the security rating is 60% dangerous. The file size is 171,520 bytes (42% of all occurrences), 155,714 bytes, 145,120 bytes or 160,992 bytes. The program has no visible window. There is no detailed description of this service. It can change the behavior of other programs or manipulate other programs. The Ymmapi.dll file is not a Windows core file.

Important: Some malware camouflages itself as Ymmapi.dll. Therefore, you should check the Ymmapi.dll process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

it is spyware designed by yahoo
it is the MAPI file to allow access to yahoo email from the email button on your browser
only when i go to check my yahoo mail this comes up and i can't check my mail
  mary wilson  
it deletes the short cuts
It is and extremely verstile dll, basically an activex control that makes yahoo mail ur default mail client. Further one of its public methods, OpenURL is used to open web sites and a lot more. Its not a spyware at all
  Rajveer Sangha  
Just a program to get mail directly from windows applications e.g. the mail button in IE
Lets you use your yahoo email account as your default e-mail client.
It's off my computer and Now I can't access email MSN
keeps showing up as error
JeNiLa is right - this program is a spyware loader designed by Yahoo. I think these people who rated it as safe work for yahoo.
i cant delete it thus i belive it is a pest!!! and i cant run yahoo no more it keeps program has already exited blah
Yahoo messenger crashes at startup. Yahoo uninstaller crashes on startup. I broke down and deleted the files manually, but cannot delete ymmapi.dll file no matter what I do. I don't use yahoo mail either.
if you cant remove it, just drag it and take it to desktop, then delete the folder it was in, and then go to your desktop and delete it
It is a link to a default mail client if you do not have Outlook
  Jimbo MCSE   (further information)
I think that when a coorperation such as yahoo or any other organization feels its their right to install and run stuff on MY system without my knowledge or concent, that they should be systematically dissmantled and the CEO's shot to make an example
this file opens a port for remote assistance for any hacker that knows how to use gain gontrol over your computor and shredd its hard drive by adding a shredder file to your locals and temps, very hard to get rid of as well, virus scan wont find it because it is covered by a yahoo name
  cooper const co  
to remove it search for yahoo and remove everything until you get an error mesage saying cannot delete this folder because write protected. just rename the folder and delate
it hides the message window of the yahoo messanger and all message u type is invisible to ourself
  mahesh gelani  
You can remove it with norton. Quarantine the file using norton, then delete it while it is quarantine.
I just think yahoo needs to stop putting bars of noobies pc's
very useful add-on for IE designed for Yahoo Mail users
  Benny Profane  
Yahoo spyware loader
it wont let me delete it. i knew it was spyware....
It's not spyware. This file is used for Yahoo! Messenger.
  Twizted   (further information)
One thing I forgot to tell you, you must unregister it from your windows registry. To do this, go to a command prompt and enter regsvr32 ymmapi.dll /u , and click enter. Robert
  Robert Rand, Deerfield Beach Fl.  
This dll allowed non client based yahoo mail (online) to be your default mail application. When installed, it show up as a listbox choice when you select tools, Internet Options, Programs, E-mail, in internet Explorer. This code is now embeded in the Yahoo Messenger, which you have to install if you want your Yahoo email to work from within web pages. If you leave it on your computer, it will mess up Yahoo mail and Yahoo messenger. You can delete it from the folder its in by first deselecting it in IE, then reboot your machine. It is now inactive and you can delete it. Robert.
  Robert Rand, Deerfiled Beach Florida  
It is definitely bad. Anytime I try to type a adress in it opens it up in yahoo search.
It is NOT spyware, some people here say it is. I made several spybot check-ups and advanced spyware of all kinds, also advanced virus scans, always I am told " No treads".
yahoo crap. hard time getting rid of it. I WIN !!!!
i know moving it didnt help, uninstalling everything yahoo didnt help, the registry thing said it canot be found, i hate yahoo and its stupid messenger and mail drives me crazy that i cant get rid of this thing! someone please clarify some of your answers? i'm fairly skilled at computers but this stumps me.
This is crap software and should be avoided
  upset AT&T customer  
You can disable it using "autoruns", which is great. You can easily re-enable it if disabling it kills something.
  fred   (further information)

Rating chart

Summary: Average user rating of Ymmapi.dll: based on 30 votes with 32 user comments. 11 users think Ymmapi.dll is essential for Windows or an installed application. One user thinks it's probably harmless. 4 users think it's neither essential nor dangerous. One user suspects danger. 13 users think Ymmapi.dll is dangerous and recommend removing it. 7 users don't grade Ymmapi.dll ("not sure about it").

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Best practices for resolving Ymmapi issues

A clean and tidy computer is the key requirement for avoiding problems with Ymmapi. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the Ymmapi.dll process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

Ymmapi.dll [all]