diff --git a/user-guide/thunderbird_for_o365.md b/user-guide/thunderbird_for_o365.md
index 815456c5..e4fc610a 100644
--- a/user-guide/thunderbird_for_o365.md
+++ b/user-guide/thunderbird_for_o365.md
@@ -61,7 +61,7 @@ With successful authentication you then close the "Account Setup" tab and enjoy
 
 ## Use O365 Default Folders
 
-Thunderbird and O365 use by default different folders for sent and deleted messages. Following guide needs only to be followed once, after Thunderbird has marked the folders on the server and other Thunderbird instances connecting to it will automatically use the correct folder. Note you then still need to do the last step to not get two copies of the same sent message in the "Sent Items" folder.
+Thunderbird and O365 use by default different folders for sent and deleted messages. Following guide needs only to be followed once, because after Thunderbird has marked the folders once on the server any other Thunderbird instance connecting to it will automatically use the correct folder. Note you then still need to do the last step to not get two copies of the same sent message in the "Sent Items" folder.
 
 ![Open Account Settings](thunderbird_for_o365/thunderbird10_account_settings.png)