An electronic device comprising: a display; a communication module; a memory; a processor operatively coupled to the memory, the electronic device configured to: display, on the display, a user interface of a messaging application; detect an input indicating a destination telephone number; transmit, via the communication module, a first message comprising a first content by using the destination telephone number and a Rich Communication Suite, RCS, protocol; receive, via the communication module, an error message indicating a transmission failure of the first message; and in response to the receipt of the error message, convert the first message to a second message based on a Multimedia Messaging Service, MMS, protocol; transmit, via the communication module, the second message comprising a second content at least a part of which is the same as the first content included in the first message, by using the destination telephone number and the MMS protocol, wherein the electronic device is configured to extract the first content including at least one of recipient information, a body text or attached file information from the first message, and convert the first message into the second message, wherein the electronic device resizes the first content by compressing or splitting the first content for generating the second content, when the first message includes a file transfer, FT, message and a file size of a file in the FT message is larger than a maximum allowable file size of the MMS protocol, wherein_the electronic device is configured to provide a popup notification that is output to a screen to provide a notification to the user that the file will be changed, the popup notification including information on file sizes of an original file and a changed file. a display; a communication module; a memory; a processor operatively coupled to the memory, the electronic device configured to: display, on the display, a user interface of a messaging application; detect an input indicating a destination telephone number; transmit, via the communication module, a first message comprising a first content by using the destination telephone number and a Rich Communication Suite, RCS, protocol; receive, via the communication module, an error message indicating a transmission failure of the first message; and in response to the receipt of the error message, convert the first message to a second message based on a Multimedia Messaging Service, MMS, protocol; transmit, via the communication module, the second message comprising a second content at least a part of which is the same as the first content included in the first message, by using the destination telephone number and the MMS protocol, wherein the electronic device is configured to extract the first content including at least one of recipient information, a body text or attached file information from the first message, and convert the first message into the second message, wherein the electronic device resizes the first content by compressing or splitting the first content for generating the second content, when the first message includes a file transfer, FT, message and a file size of a file in the FT message is larger than a maximum allowable file size of the MMS protocol, wherein_the electronic device is configured to provide a popup notification that is output to a screen to provide a notification to the user that the file will be changed, the popup notification including information on file sizes of an original file and a changed file. display, on the display, a user interface of a messaging application; detect an input indicating a destination telephone number; transmit, via the communication module, a first message comprising a first content by using the destination telephone number and a Rich Communication Suite, RCS, protocol; receive, via the communication module, an error message indicating a transmission failure of the first message; and in response to the receipt of the error message, convert the first message to a second message based on a Multimedia Messaging Service, MMS, protocol; transmit, via the communication module, the second message comprising a second content at least a part of which is the same as the first content included in the first message, by using the destination telephone number and the MMS protocol, wherein the electronic device is configured to extract the first content including at least one of recipient information, a body text or attached file information from the first message, and convert the first message into the second message, wherein the electronic device resizes the first content by compressing or splitting the first content for generating the second content, when the first message includes a file transfer, FT, message and a file size of a file in the FT message is larger than a maximum allowable file size of the MMS protocol, wherein_the electronic device is configured to provide a popup notification that is output to a screen to provide a notification to the user that the file will be changed, the popup notification including information on file sizes of an original file and a changed file.