To reply to a Twitter mention from the Inbox, first, click on the mention. Then, type in your reply into the provided field. You can add emojis, a picture, or a video attachment. The max file size for an attached image is 5 Mb, for GIFs it's 15 Mb, and for video, it's 30 Mb. Standard file formats are supported - JPEG, PNG, GIF, MOV, MP4, AVI.
You can also use one of the saved replies, or create one if you haven't done so yet. Learn more about saved replies here.
If you are replying to multiple Twitter users mentioned in one thread, their usernames (Twitter handles) will not be counted against the 280 characters limit. You can leave out any username in the conversation by unchecking it, except the original author of the mention you are replying to.
It's only possible to reply to the last mention within the conversation thread, not to the preceding ones.
Replying to a direct Twitter message is also easy - click on the incoming message in Inbox and type the reply into the provided field. You can add emojis, or an image or video attachment. Same file size/format specs apply, as for mentions (see above).
You can use saved replies, or create a new one.
The direct message can't be longer than 10,000 characters. You cannot send a blank message.
Twitter created restrictions on sending links through DMs. If you can't send a link through DM and you are seeing an error message, it means Twitter doesn't allow you to send this link to this follower. You'll find the same behaviour on Twitter. There's nothing we can do :/
Also, if you see the following error message, it means the user who you're trying to send the direct message has blocked you - in such a case, it's not possible to send DM.
Twitter error: This code is used when requests are being denied due to update limits (https://support.twitter.com/articles/15364-about-twitter-limits-update-api-dm-and-following). message - You cannot send messages to users who are not following you. code - 150